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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-K
(Mark One)
ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the fiscal year ended December 31, 2020
OR
TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM _________ TO _________

Commission File Number: 001-39263
 
Zentalis Pharmaceuticals, Inc.
(Exact name of Registrant as specified in its Charter)
Delaware82-3607803
(State or other jurisdiction of
incorporation or organization)
(I.R.S. Employer
Identification No.)
530 Seventh Avenue, Suite 2201
New York, New York

(Address of principal executive offices)
10018
(Zip Code)
Registrant's telephone number, including area code (212) 433-3791
Securities registered pursuant to Section 12(b) of the Act:
Title of each classTrading Symbol(s)Name of each exchange on which registered
Common stock,
$0.001 par value per share
ZNTLThe Nasdaq Global Market
Securities registered pursuant to Section 12(g) of the Act: None
(Title of class)
Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes No
Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes No
Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12-months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes      No   
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes     No   
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and "emerging growth company" in Rule 12b-2 of the Exchange Act.
Large accelerated filer
Accelerated filer
Non-accelerated filer  
Small reporting company
Emerging growth company
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.  

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).     Yes    No  
The aggregate market value of the voting and non-voting stock held by non-affiliates of the registrant, as of June 30, 2020, the last business day of the registrant's most recently completed second fiscal quarter, was approximately $1.15 billion based on the closing price of $48.02 as reported on the Nasdaq Global Select Market on such date. Solely for the purposes of this disclosure, shares of common stock held by executive officers, directors and certain stockholders of the registrant as of such date have been excluded because such holders may be deemed to be affiliates.
The number of shares of registrant's common stock outstanding as of March 24, 2021 was 41,040,286.

DOCUMENTS INCORPORATED BY REFERENCE
Portions of the registrant's definitive Proxy Statement relating to its 2021 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2020 are incorporated herein by reference in Part III.



TABLE OF CONTENTS
 
Page






BASIS OF PRESENTATION

Except where the context otherwise requires or where otherwise indicated, the terms “Zentalis,” “we,” “us,” “our,” “our company,” “Company” and “our business” refer: (1) following the consummation of our statutory conversion to a Delaware corporation on April 2, 2020, or the Corporate Conversion, in connection with our initial public offering, or IPO, to Zentalis Pharmaceuticals, Inc. and (2) prior to the completion of the Corporate Conversion, to Zentalis Pharmaceuticals, LLC.

The consolidated audited financial statements include the accounts of Zentalis Pharmaceuticals, LLC and its subsidiaries. In connection with our IPO, in April 2020, Zentalis Pharmaceuticals, LLC converted into a Delaware corporation pursuant to a statutory conversion, and changed its name to Zentalis Pharmaceuticals, Inc. All holders of units of Zentalis Pharmaceuticals, LLC became holders of shares of common stock of Zentalis Pharmaceuticals, Inc. In this Annual Report on Form 10-K, we refer to all transactions related to our conversion to a corporation as the Corporate Conversion.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward-looking statements. We intend such forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. All statements other than statements of historical facts contained in this Annual Report on Form 10-K are forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplate,” “believe,” “estimate,” “forecast,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements contained in this Annual Report on Form 10-K include, but are not limited to, statements regarding our future results of operations and financial position, the anticipated impact of the COVID-19 pandemic on our business, business strategy, prospective products and product candidates, clinical trial timelines and expected timing for the release of data, research and development costs, future revenue, timing and likelihood of success, potential collaboration opportunities and plans and objectives of management.

The forward-looking statements in this Annual Report on Form 10-K are only predictions and are based largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this Annual Report on Form 10-K and are subject to a number of known and unknown risks, uncertainties, assumptions and other important factors, including those described under the sections in this Annual Report on Form 10-K entitled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and elsewhere in this Annual Report on Form 10-K.

Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward-looking statements as predictions of future events. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise.

TRADEMARKS AND TRADENAMES

Solely for convenience, trademarks, service marks and tradenames referred to in this Annual Report on Form 10-K may appear without the ®, TM or SM symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or the right of the applicable licensor to these trademarks, service marks and tradenames. This Annual Report on Form 10-K may also contain trademarks, service marks, tradenames and copyrights of other companies, which are the property of their respective owners.

INDUSTRY AND OTHER DATA

This Annual Report on Form 10-K contains industry, market and competitive position data from our own internal estimates and research as well as industry and general publications and research surveys and studies conducted by third parties. Industry publications, studies and surveys generally state that they have been obtained from sources believed to be reliable, although they do not guarantee the accuracy or completeness of such information. Our internal data and estimates are based upon information obtained from trade and business organizations and other contacts in the markets in which we operate and our management’s understanding of industry conditions. While we believe that each of these studies and publications is reliable, we have not independently verified market and industry data from third-party sources. While we believe our internal company



research is reliable and the market definitions are appropriate, neither such research nor definitions have been verified by an independent source.

The industry in which we operate is subject to risks and uncertainties due to a variety of factors, including those described in Part I, Item 1A., “Risk Factors” in this Annual Report on Form 10-K. These and other factors could cause results to differ materially from those expressed in the estimates made by the independent parties and by us.





SUMMARY RISK FACTORS

Our business is subject to numerous risks and uncertainties, including those described in Part I, Item 1A., “Risk Factors” in this Annual Report on Form 10-K. You should carefully consider these risks and uncertainties when investing in our common stock. The principal risks and uncertainties affecting our business include the following:

We have a limited operating history, have not completed any clinical trials and have no products approved for commercial sale, which may make it difficult for you to evaluate our current business and predict our future success and viability.

We have incurred significant net losses since inception and we expect to continue to incur significant net losses for the foreseeable future.

We will require substantial additional capital to finance our operations. If we are unable to raise such capital when needed, or on acceptable terms, we may be forced to delay, reduce or eliminate one or more of our research and drug development programs or future commercialization efforts.

We are substantially dependent on the success of our lead product candidates, ZN-c5 and ZN-c3, which are currently in clinical trials. If we are unable to complete development of, obtain approval for and commercialize ZN-c5 and/or ZN-c3 in a timely manner, our business will be harmed.

The outcome of preclinical testing and early clinical trials may not be predictive of the success of later clinical trials, and the results of our clinical trials may not satisfy the requirements of the FDA, EMA or other comparable foreign regulatory authorities.

We may face additional risks associated with the development of ZN-c5, ZN-c3, ZN-d5, ZN-e4 and potentially other product candidates in combination with other therapies.

The clinical trial and regulatory approval processes are lengthy, time-consuming and inherently unpredictable, and we may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development and commercialization of our product candidates.

The competition for qualified personnel is particularly intense in our industry. If we are unable to retain or hire key personnel, then we may not be able to sustain or grow our business.

We face significant competition and, if our competitors develop and market technologies or products more rapidly than we do or that are more effective, safer or less expensive than the product candidates we develop, our commercial opportunities will be negatively impacted.

Our success depends on our ability to protect our intellectual property and our proprietary platform. If we are unable to adequately protect our intellectual property and our proprietary platform, or to obtain and maintain issued patents which are sufficient to protect our product candidates, then others could compete against us more directly, which would negatively impact our business.

Our existing collaborations are important to our business and future licenses may also be important to us and, if we are unable to maintain any of these collaborations, or if these arrangements are not successful, our business could be adversely affected.

We rely, and expect to continue to rely, on third parties, including independent clinical investigators and CROs, to conduct certain aspects of our preclinical studies and clinical trials. If these third parties do not successfully carry out their contractual duties, comply with applicable regulatory requirements or meet expected deadlines, we may not be able to obtain regulatory approval for or commercialize our product candidates and our business could be substantially harmed.

Our commercial success depends significantly on our ability to operate without infringing the patents and other proprietary rights of third parties. Claims by third parties that we infringe their proprietary rights may result in liability for damages or prevent or delay our developmental and commercialization efforts.

The COVID-19 pandemic has adversely impacted, and we expect will continue to adversely impact, our business, including our preclinical studies and clinical trials.



PART I
Item 1. Business.
Overview
We are a clinical-stage biopharmaceutical company focused on discovering and developing small molecule therapeutics targeting fundamental biological pathways of cancers. We use our highly efficient drug discovery engine, which we refer to as our Integrated Discovery Engine, to identify targets and develop small molecule new chemical entities, or NCEs, with properties that we believe could result in potentially differentiated product profiles. Our discovery engine combines our extensive experience and capabilities across cancer biology and medicinal chemistry. We believe our product candidates are differentiated from current programs targeting similar pathways and, if approved, have the potential to significantly impact clinical outcomes of patients with cancer.
We are developing a broad pipeline of product candidates, with an initial focus on validated oncology targets with the potential to address large patient populations. We currently have two (2) lead product candidates - ZN-c5 and ZN-c3. ZN-c5 is an oral selective estrogen receptor degrader, or SERD, currently in a Phase 1/2 clinical trial for the treatment of advanced estrogen receptor-positive, human epidermal growth factor receptor 2-negative, or ER+/HER2-, advanced or metastatic breast cancer. We have designed ZN-c5 to have high potency and selectivity, as well as favorable tolerability and pharmacokinetic, or PK, properties. We intend to initiate the Phase 2 monotherapy and combination portions of this Phase 1/2 trial in the first half of 2021. ZN-c3, an inhibitor of WEE1, a protein tyrosine kinase, is currently being evaluated in a Phase 1/2 clinical trial for the treatment of advanced solid tumors as a monotherapy and in a Phase 1b clinical trial in combination with chemotherapy in patients with advanced ovarian cancer. We plan to present initial data from the Phase 1 portion of the Phase 1/2 monotherapy trial at the 2021 American Association of Cancer Research (AACR) Annual Meeting. In 2021, we intend to initiate a Phase 2 monotherapy trial for uterine serous carcinoma, or USC, and two (2) additional Phase 1 clinical trials evaluating ZN-c3 in combination with chemotherapy and PARP inhibitor in ovarian cancer and other targeted indications.
Our other clinical product candidates include ZN-d5, a selective inhibitor of B-cell lymphoma 2, or BCL-2, currently in Phase 1 clinical trial for the treatment of non-Hodgkin's lymphoma, or NHL, and acute myelogenous leukemia, or AML, and ZN-e4, an irreversible inhibitor of mutant epidermal growth factor receptor, or EGFR, currently in a Phase 1/2 clinical trial for the treatment of advanced non-small cell lung cancer, or NSCLC.
We plan to explore the combination potential of ZN-c5, our oral SERD, with ZN-d5, our BCL-2 inhibitor, for the treatment of ER+/HER2- breast cancer. We expect to report topline results from the Phase 1 portion of the ongoing trials of each of ZN-c5, ZN-c3 and ZN-e4 in 2021. We currently own worldwide development and commercialization rights to each of our product candidates, other than in select Asian countries (including China) for each of ZN-c5, ZN-c3 and ZN-d5, for which we have out-licensed these rights to our majority-owned joint venture, Zentera Therapeutics (Cayman), Ltd., or Zentera, and for ZN-e4, for which we have out-licensed these rights to SciClone Pharmaceuticals International (Cayman) Development Ltd., or SciClone.
The following table summarizes our product candidate pipeline.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g1.jpg
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(1) We are currently evaluating ZN-c5 in combination with palbociclib, as part of a clinical research collaboration with Pfizer, and are evaluating ZN-c5 in combination with abemaciclib, as part of a clinical research collaboration with Eli Lilly and Company, or Lilly. We maintain full ownership of ZN-c5 in each such collaboration. SciClone has development and commercial rights to ZN-e4 in Greater China (including Macau and Hong Kong), South Korea, Taiwan and Vietnam. Zentera, our majority-owned joint venture, has development and commercial rights to ZN-c5, ZN-c3 and ZN-d5 in select Asian countries (including China). Zentera submitted an investigational new drug application, or IND, in China for ZN-c5 in December 2020, for ZN-c3 in February 2021, and intends to submit for ZN-d5 in 2021.
We are also currently advancing multiple small molecule programs in preclinical development for other cancer indications, including select solid tumors and hematological malignancies. We are now in lead optimization for our fifth product candidate and plan to submit an IND to the FDA in 2021.
In the six (6) years since our inception, we have successfully cleared four (4) INDs with the FDA, and expect to submit a fifth IND in 2021. Our Integrated Discovery Engine has enabled us to take each of our clinical-stage product candidates from initial discovery to IND submission in less than three (3) years in a capital efficient manner. We begin our process of drug discovery by identifying fundamental biological pathways of cancers based upon a number of factors, including validation of the pathway through prior clinical outcomes and ability to impact large patient populations. We then analyze existing marketed products and compounds in development that target these cancer pathways and assess their limitations, efficacy, safety, tolerability, PK, patient convenience and potential to be used in combination with other therapies. Next, we use our medicinal chemistry expertise and extensive understanding of target-drug structure activity to design proprietary NCEs with properties that we believe can address observed limitations and suboptimal drug characteristics of marketed products or other compounds in development, including potency, solubility, route of administration and PK properties. We believe overcoming these limitations may also allow us to develop these product candidates for use in combination with other therapies, including with our internally-developed product candidates, if approved. Finally, we strive to generate preclinical data to support that such candidates could have a differentiated product profile in our expected lead indications before advancing a compound into clinical development. We have used our Integrated Discovery Engine to generate a pipeline of four (4) product candidates targeting solid tumors and hematological malignancies. Longer term, we believe our discovery engine has the potential to generate product candidates addressing a wide range of additional therapeutic areas.
ZN-c5, one of our lead product candidates, is an oral SERD for the treatment of ER+/HER2- advanced or metastatic breast cancer. ER+/HER2- breast cancer affects approximately 70% of all breast cancer patients in the United States. These tumors depend on the estrogen receptor, or ER, for growth and survival, and are currently treated by a number of approved hormonal therapies. We have designed ZN-c5 to overcome limitations of existing hormonal therapies, including the only FDA-approved SERD, fulvestrant (marketed as Faslodex® by AstraZeneca). Despite its limitations, Faslodex® generated worldwide sales of over $1.0 billion in 2018 (the last year prior to generic competition), reflecting part of the significant potential of the SERD therapeutic class in ER+/HER2- breast cancer.
We believe ZN-c5, which is being developed for convenient oral administration, has the potential to be used as monotherapy and in combinations, and could become the standard of care for hormonal therapy in the treatment of all lines of ER+/HER2- breast cancer, if approved. We are currently evaluating ZN-c5 in a Phase 1/2 clinical trial in patients with ER+/HER2- advanced or metastatic breast cancer, both as monotherapy and in combination with palbociclib (marketed as Ibrance® by Pfizer) as part of a clinical research collaboration with Pfizer. Palbociclib is an inhibitor of cyclin dependent kinases 4 and 6, or CDK4/6, and is FDA approved for ER+/HER2- advanced or metastatic breast cancer patients in combination with hormonal therapies, such as fulvestrant. In addition, we initiated a Phase 1b open label, multi-center trial evaluating ZN-c5 in combination with abemaciclib (marketed as Verzenio® by Lilly) in patients with ER+/HER2- advanced or metastatic breast cancer in November 2020 as part of a clinical research collaboration with Lilly. Abemaciclib is a CDK4/6 inhibitor FDA approved for the treatment of HR+/HER2- advanced or metastatic breast cancer patients in combination with fulvestrant, aromatase inhibitors or as a single agent in certain patients with disease progression following treatment with prior endocrine therapy or chemotherapy regimens.
We believe ZN-c5, if approved, may have a potentially differentiated product profile. Based on results from our ongoing Phase 1/2 clinical trial as of the database cutoff date of June 30, 2020, the PK of ZN-c5, as monotherapy and in combination with palbociclib, was characterized by rapid absorption into the systemic circulation and high drug exposure levels. Six (6) of the 15 patients in the Phase 1, monotherapy dose escalation portion of the trial showed stable disease for 24 weeks, leading to a clinical benefit rate of 40% as of such date. In addition, ZN-c5 has been observed to be well tolerated with no dose-limiting toxicities reported. In preclinical studies, ZN-c5 has shown anti-tumor activity, potency and selectivity. We intend to initiate the Phase 2 monotherapy and combination portions of the Phase 1/2 trial in the first half of 2021. We are also currently dosing ZN-c5 in a Phase 1 Window of Opportunity study in patients with ER+/HER2- breast cancer scheduled to undergo surgical resection of the tumor or start neoadjuvant treatment. We expect to report topline results of the Window of Opportunity study in the first half of 2021. In addition, we intend to initiate, subject to feedback from the FDA, a Phase 2/3 clinical trial evaluating
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ZN-c5 in earlier stage breast cancer patients in 2021 and to initiate a Phase 1b clinical trial evaluating ZN-c5 in combination with ZN-d5, our BCL-2 inhibitor product candidate, in patients with ER+/HER2- breast cancer in 2021.
Our other lead product candidate, ZN-c3, is an oral, small molecule inhibitor of WEE1, a DNA damage response protein. The inhibition of WEE1 aims to allow sufficient DNA damage in cancer cells to cause them to undergo programmed cell death, or apoptosis, thereby preventing tumor growth and potentially causing tumor regression. There is currently no FDA-approved WEE1 inhibitor. We believe ZN-c3, if approved, may have broad applicability in a wide range of cancers as monotherapy and in combination, including with chemotherapy agents and other targeted therapies. Based on data from 22 patients dosed in the Phase 1 monotherapy dose escalation portion of our ongoing Phase 1/2 clinical trial as of the database cutoff date of June 19, 2020, ZN-c3 has been observed to be well tolerated with no dose limiting toxicities reported. We are currently conducting a Phase 1/2 clinical trial of ZN-c3 in patients with advanced solid tumors. We plan to report results from the Phase 1 portion of this trial at the AACR Annual Meeting in April 2021. In addition, we initiated a Phase 1b clinical trial evaluating ZN-c3 in combination with chemotherapy in patients with advanced ovarian cancer in October 2020 and plan to initiate a Phase 2 trial evaluating ZN-c3 as monotherapy in patients with uterine serous carcinoma, or USC, in 2021. USC comprises 10%, and has the highest mortality rate, of all endometrial cancers, with approximately 6,000 new cases and 4,500 deaths in the United States per year. We continue to actively evaluate other potential combinations for the future clinical development of ZN-c3, and intend to initiate two (2) additional Phase 1 clinical trials evaluating ZN-c3 in combination with chemotherapy and PARP inhibitor in ovarian cancer and other targeted indications in 2021.
ZN-d5 is our oral, small molecule inhibitor of BCL-2, a protein that is designed to inhibit programmed cell death. BCL-2 is a validated target in a wide variety of malignancies and we are initially developing ZN-d5 for the treatment of hematologic malignancies. In the third quarter of 2020, we initiated a Phase 1 clinical trial of ZN-d5 in patients with NHL and AML. We intend to initiate a Phase 1b clinical trial evaluating ZN-d5 in combination with ZN-c5, our oral SERD product candidate, in patients with ER+/HER2- breast cancer in 2021.
ZN-e4 is our oral, small molecule product candidate being developed as an irreversible inhibitor of mutant EGFR. EGFR regulates a number of cellular functions, including cell proliferation and survival, and is a driver of tumor growth in certain cancers, including lung cancer. We have designed ZN-e4 to be highly selective against mutant EGFR. We are conducting a Phase 1/2 clinical trial of ZN-e4 in patients with advanced NSCLC with activating EGFR mutations and are currently evaluating potential combination therapies for future clinical development of ZN-e4. We expect to report topline results from the Phase 1 portion of the trial in 2021.
Pursuant to a collaboration and license agreement entered into in May 2020, we collaborate with Zentera, our majority-owned joint venture, on the development and commercialization of ZN-c5, ZN-c3 and ZN-d5 in select Asian countries (including China). Zentera submitted an IND in China for ZN-c5 in December 2020, for ZN-c3 in February 2021, and intends to submit for ZN-d5 in 2021.
Our History and Team
We began operations in January 2015. We have assembled a management team of biopharmaceutical experts with extensive experience in building and operating organizations that develop and deliver innovative medicines to patients. Our management team has broad expertise and successful track records in drug discovery, clinical development, regulatory affairs, manufacturing and commercialization of cancer therapies, as well as in business and finance, through previous experiences at leading institutions including Aisling Capital, Array Biopharma, Bayer Healthcare, Celgene, CureVac AG, Eisai US, Goldman Sachs, IQVIA, Merck, Morgan Stanley, Novartis, Paratek Pharmaceuticals, Pfizer, PsiOxus Therapeutics and R-Pharm US.
We are guided by our board of directors, scientific advisory board and business advisory board. Our scientific advisory board works with our management team in planning, development and execution of scientific, clinical, and research and development initiatives and strategies, while our business advisory board works with our management team on business and operational initiatives and strategies. Our renowned scientific and business advisory boards are comprised of key scientific and clinical thought leaders in oncology: Stephen Ansell, M.D., Ph.D., Andrew Badley, M.D., Robert Glassman, M.D., Shaji Kumar, M.D., Anthony Letai, M.D., Ph.D., Ross Levine, M.D., Donald McDonnell, Ph.D., Chad Robins, M.B.A. and Kwok-Kin Wong, M.D., Ph.D. These individuals are associated with the following leading institutions: Adaptive Biotechnologies, Credit Suisse, Duke University, Harvard Medical School, Mayo Clinic, Memorial Sloan Kettering Cancer Center and NYU Langone Health.
We believe our experienced and diverse team is well positioned to leverage our highly efficient Integrated Discovery Engine to identify targets and develop small molecule NCEs targeting fundamental biological pathways of cancers that are differentiated from existing marketed therapies by clinical performance, and to address large patient populations.
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Strategy
Our goal is to become a leading oncology-focused biopharmaceutical company. Our strategy includes the following key components:
 
Discover and develop differentiated small molecule NCEs that address large patient populations with cancer. We have leveraged our broad industry experience and know-how, and the guidance of our scientific and business advisory boards, to build our Integrated Discovery Engine. This engine integrates our extensive capabilities across cancer biology and medicinal chemistry. We use our Integrated Discovery Engine to identify validated and fundamental targets and develop small molecule NCEs that are differentiated from existing marketed therapies by clinical performance, and, if approved, could offer meaningful benefits for patients. In addition, in April 2020, we entered into a discovery platform agreement with Tavros Therapeutics, Inc., or Tavros, to apply Tavros’ functional genomic discovery platform to develop next generation targeted small molecule drug candidates, with an initial goal of expanding our oncology product candidate pipeline. In February 2021, we announced a strategic collaboration to leverage Tempus’ patient-derived organoid biological modeling platform to strengthen Zentalis’ discovery and research capabilities. Tempus’ proprietary platform has the ability to grow and recapitulate tumors both genetically and functionally, some of which can be used for DNA repair profiling and therapeutic sensitivity testing. In harnessing Tempus’ cutting-edge approach, the collaboration will initially aim to evaluate Zentalis’ WEE1 inhibitor, ZN-c3, and its DNA damage response pathway in genetically distinct patient populations. The platform will also be used to investigate additional novel targets of cancer pathways identified by Zentalis, as well as support the study of Zentalis’ current product candidates across various indications. Zentalis retains full ownership of its therapeutic candidates. We will continue to pursue other opportunities for new technologies to enhance the Zentalis approach.
Rapidly advance the development of our lead product candidates, ZN-c5 (oral SERD) and ZN-c3 (WEE1 Inhibitor), toward regulatory approval. We have designed ZN-c5 to overcome limitations of existing hormonal therapies including fulvestrant, the only FDA-approved SERD. Based on data observed in our preclinical studies and results from our ongoing Phase 1/2 clinical trial, we believe ZN-c5, if approved, may have a differentiated product profile. We are evaluating ZN-c5 as a treatment of ER+/HER2- advanced or metastatic breast cancer. ER+/HER2- breast cancer affects approximately 70% of all breast cancer patients in the United States. We are currently evaluating ZN-c5 in an ongoing Phase 1/2 clinical trial in patients with ER+/ HER2- advanced or metastatic breast cancer both as monotherapy and in combination with palbociclib and in an ongoing Phase 1 Window of Opportunity study in patients with ER+/HER2- breast cancer scheduled to undergo surgical resection of the tumor or start neoadjuvant treatment. We intend to initiate the Phase 2 monotherapy and combinations portions of the Phase 1/2 trial, and to report topline results of the Window of Opportunity study, in the first half of 2021. In addition, in November 2020, we initiated a Phase 1b open label, multi-center trial evaluating ZN-c5 in combination with abemaciclib in patients with ER+/HER2- advanced or metastatic breast cancer as part of a clinical research collaboration with Lilly. In 2021, we intend to initiate a Phase 1b clinical trial evaluating ZN-c5 in combination with ZN-d5, our BCL-2 inhibitor product candidate, in patients with ER+/HER2- breast cancer, and, subject to feedback from the FDA, a Phase 2/3 clinical trial evaluating ZN-c5 in earlier stage breast cancer patients.We are currently evaluating ZN-c3 in a Phase 1/2 monotherapy clinical trial for the treatment of advanced solid tumors and in a Phase 1b clinical trial in combination with chemotherapy in advanced ovarian cancer. We plan to report initial topline results from the ongoing clinical trials of ZN-c3 at the 2021 American Association of Cancer Research (AACR) Annual Meeting. In 2021, we intend to initiate a Phase 2 clinical trial evaluating ZN-c3 as monotherapy in patients with USC, and two (2) additional Phase 1 clinical trials evaluating ZN-c3 in combination with chemotherapy and PARP inhibitor in ovarian cancer and other targeted indications.
Advance our additional product candidates, ZN-d5 (BCL-2 Inhibitor) and ZN-e4 (EGFR Inhibitor), across multiple cancer indications. We are advancing the development of our other small molecule NCEs targeting fundamental biological cancer pathways. These product candidates are designed to be small molecule NCEs with differentiated product profiles. ZN-d5 is currently in a Phase 1 clinical trial in NHL and AML and ZN-e4 is currently in a Phase 1/2 clinical trial for the treatment of advanced NSCLC. We expect to report topline results from the Phase 1 portions of the ongoing clinical trials of ZN-e4 in 2021. We also intend to initiate a Phase 1b clinical trial evaluating ZN-d5 in combination with ZN-c5 in patients with ER+/HER2- breast cancer in 2021.
Continue to evaluate our product candidate pipeline in combination with internally discovered and third-party compounds. We believe the future of cancer treatment is to target multiple fundamental biological pathways through combination therapies. In our preclinical studies and clinical trials, our product candidates have shown the potential for combination with other approved and development- stage cancer therapies. For example, we are dosing ZN-c5, our oral SERD, in combination with palbociclib for the treatment of ER+/HER2- advanced or metastatic breast cancer and, in November 2020, we initiated a Phase 1b clinical trial evaluating ZN-c5 in combination with abemaciclib for the treatment of ER+/HER2- advanced or metastatic breast cancer. We also plan
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to explore other potential combinations for our product candidates with internally developed compounds. For example, we plan to explore the combination potential of ZN-d5, our BCL-2 inhibitor, with ZN-c5, our oral SERD, for the treatment of breast cancer.
Deploy our highly efficient Integrated Discovery Engine to further expand our product candidate pipeline. Our robust product candidate pipeline is enabled by our highly efficient drug discovery engine, which we plan to continue to leverage to discover and develop additional differentiated small molecule NCEs for the treatment of cancer. In the six (6) years since our inception, we have successfully cleared four (4) INDs with the FDA and expect to submit a fifth IND in 2021. Our Integrated Discovery Engine has enabled us to take our clinical-stage product candidates from initial discovery to acceptance of IND in less than three (3) years per program and in a capital efficient manner. We are also currently advancing multiple small molecule programs in preclinical studies for other cancer indications, including select solid tumors and hematological malignancies.
Evaluate strategic opportunities to accelerate development timelines and maximize the value of our product candidate pipeline. We currently own the worldwide development and commercial rights to each of our product candidates, other than in select Asian countries (including China) for each of ZN-c5, ZN-c3 and ZN-d5, for which we have outlicensed these rights to Zentera, our majority-owned joint venture, and for ZN-e4, for which we have out-licensed these rights to SciClone. We intend to evaluate additional collaborations that could maximize the value of our product candidate pipeline, either through the evaluation of our product candidates in combination with compounds owned by third-parties or through geographic collaborations outside of the United States that allow us to leverage the existing infrastructure of other companies.

Our Zentalis Approach
We have leveraged our extensive industry experience and know-how, and the guidance of our scientific advisory board, to build our Integrated Discovery Engine that integrates our extensive capabilities across cancer biology and medicinal chemistry. This engine enables us to identify targets for which small molecule NCEs with high potency, high exposure and other optimized drug properties could yield potentially differentiated product profiles. Our approach centers on utilizing our Integrated Discovery Engine to identify such targets and subsequently develop product candidates that address targets with large cancer patient populations. At the core of our Integrated Discovery Engine is our experienced and proven management team, as well as our renowned chemistry team that has over 150 years of combined discovery expertise and who have collectively brought 35 product candidates into clinical development, including 27 oncology product candidates. Due in large part to our Integrated Discovery Engine, we have four (4) active INDs with the FDA, and expect to submit a fifth IND in 2021.
Our Integrated Discovery Engine is executed through the following process:
 
First, identify fundamental biological pathways of cancers, considering a number of factors, including prior clinical outcomes, input from our scientific and business advisory boards, large unmet medical need and market opportunity.
Second, identify and analyze key products or compounds targeting these cancer pathways and assess their limitations, including with respect to efficacy, safety, tolerability, PK, patient convenience and their potential to be used in combination.
Third, use our medicinal chemistry expertise and deep understanding of target-drug structure activity relationships to create proprietary NCEs that are designed to improve upon and address observed limitations of existing products or compounds.
Fourth, generate strong preclinical data to support our view that such candidates could have potentially differentiated product profiles in our expected lead indications, if approved, before moving a compound into clinical development.
We have initially chosen to focus on targets that have been validated clinically and, in most cases, commercially. This provides us with a clear understanding of the indications we will target and endpoints that have been required for regulatory approval of products for these indications in the past, as well as the potential for clinical adoption and commercial success. This strategy has enabled us to begin our drug discovery and development process at an advanced state relative to where the process would otherwise begin in focusing on uncharacterized targets. We believe this ability provides us with an efficient path to identifying novel drug compounds and advancing them into clinical development in a capital efficient manner.

Our Product Candidates
ZN-c5, an Oral SERD for the Treatment of ER+/HER2- Breast Cancer
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Overview
We are developing ZN-c5, an oral, small molecule product candidate targeting the ER, a key driver of tumor growth and survival in ER+/HER2- breast cancer. These tumors are currently treated by a number of hormonal therapies; however, in contrast to most ER binders that simply block or modulate ER activity, ZN-c5 is also designed to cause degradation of the ER. As such, ZN-c5 is known as a Selective ER Degrader, or SERD. Fulvestrant, marketed as Faslodex® by AstraZeneca, is currently the only FDA-approved SERD. While effective, fulvestrant is limited to its FDA-approved dosing regimen of two (2) painful 5 mL concomitant monthly intramuscular injections, thus restricting the level of ER degradation that can be induced in patients, which we believe limits its efficacy. We have applied our expertise to design ZN-c5 as an oral potent and selective SERD with characteristics which we believe may result in a differentiated product profile. We believe ZN-c5, if approved, has the potential to be used as monotherapy and in combinations and could become the standard of care for hormonal therapy in the treatment of all lines of ER+/HER2- breast cancer.
We are currently conducting a Phase 1/2 clinical trial of ZN-c5 in patients with ER+/HER2- advanced or metastatic breast cancer. ER+/HER2- breast cancer affects approximately 70% of all breast cancer patients in the United States. We continue to enroll patients and collect data for ZN-c5 administered as monotherapy and in combination with palbociclib as part of a clinical research collaboration with Pfizer. Palbociclib, marketed as Ibrance®, is a CDK4/6 inhibitor that is FDA approved for the treatment of ER+/HER2- advanced or metastatic breast cancer in combination with hormonal therapies, such as fulvestrant. In addition, in November 2020, we initiated a Phase 1b open label, multi-center trial evaluating ZN-c5 in combination with abemaciclib (marketed as Verzenio® by Lilly) in patients with ER+/HER2- advanced or metastatic breast cancer as part of a clinical research collaboration with Lilly. Abemaciclib is a CDK4/6 inhibitor FDA approved for the treatment of HR+/HER2- advanced or metastatic breast cancer in combination with fulvestrant, aromatase inhibitors or as a single agent in certain patients with disease progression following treatment with prior endocrine therapy or chemotherapy regimens. We maintain full ownership of ZN-c5 in each collaboration.
We intend to initiate the Phase 2 monotherapy and combination portions of the Phase 1/2 trial in the first half of 2021. We are also currently dosing ZN-c5 in a Phase 1 Window of Opportunity study in patients with ER+/HER2- breast cancer scheduled to undergo surgical resection of the tumor or start neoadjuvant treatment. We expect to report topline results of the Window of Opportunity study in the first half of 2021. In addition, we intend to initiate, subject to feedback from the FDA, a Phase 2/3 clinical trial evaluating ZN-c5 in earlier stage breast cancer patients in 2021 and to initiate a Phase 1b clinical trial evaluating ZN-c5 in combination with ZN-d5, our BCL-2 inhibitor product candidate, in patients with ER+/HER2- breast cancer in 2021.
Background on Breast Cancer and Current Treatments
Breast cancer is the most prevalent cancer in women, accounting for 30% of all female cancers and 13% of cancer-related deaths in the United States. The National Cancer Institute estimated that approximately 275,000 new cases of breast cancer would be diagnosed in the United States in 2020, and approximately 42,000 breast cancer patients would die of the disease.
Most breast cancer tumor growth is dependent on two (2) main protein receptors: estrogen receptor and human epidermal growth factor receptor 2. Approximately 70% of breast cancers in the United States are ER+/HER2-, meaning that they express ER and not HER2, and therefore depend on estrogen signaling for tumor growth and survival. These ER+ tumors are sometimes referred to as hormone receptor positive, or HR+ tumors, and are currently treated using several approaches:
 
by blocking receptor function with selective ER modulators, or SERMs;
by blocking the synthesis of these hormones with aromatase inhibitors, or AIs; or
by degrading, and thus potentially eliminating ER receptors with a drug in the SERD class.
AIs have demonstrated superior clinical benefit to SERMs, including tamoxifen, and SERDs have demonstrated superior clinical benefit to AIs.
FDA-Approved SERD, Fulvestrant, and its Limitations
Currently, fulvestrant is the only FDA-approved SERD. Fulvestrant is FDA-approved for first and second-line treatment for women with HR+/HER2- advanced breast cancer both as monotherapy and as combination therapy with a number of other drug classes. Fulvestrant has demonstrated improved efficacy relative to AIs. In a randomized double-blind, placebo-controlled trial in treatment of naïve advanced and metastatic breast cancer patients, treatment with 500 mg of fulvestrant resulted in median progression free survival, or PFS, of 16.6 months versus 13.8 months for anastrozole, an FDA-approved oral AI marketed as Arimidex® by ANI Pharmaceuticals. However, fulvestrant has a number of pharmacological characteristics that
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require it to be delivered via two (2) painful 5 mL concomitant monthly intramuscular injections, which we believe may limit its efficacy and tolerability. Despite these limitations, AstraZeneca reported worldwide sales of Faslodex® of over $1.0 billion in 2018, the last year prior to generic competition.
We believe the following limitations associated with fulvestrant create an opportunity to develop a SERD with a superior product profile:
 
Route of administration. Fulvestrant is highly insoluble and must be given via painful intramuscular injection. Fulvestrant is dosed monthly following two (2) initial loading doses administered two (2) weeks apart, and can only be delivered via two (2) painful 5 mL concomitant monthly intramuscular injections.
Capped efficacy in humans. Results of third-party clinical trials have shown that higher doses of fulvestrant increased ER degradation and efficacy. In a randomized Phase 2 clinical trial evaluating fulvestrant in 211 postmenopausal women with ER+ locally advanced or metastatic breast cancer, 250 mg and 500 mg of fulvestrant achieved a mean change of 14% and 50% of ER degradation, respectively, in each case measured at week 4 from dosing. In addition, in a Phase 3 clinical trial, the 500 mg dose arm achieved a median overall survival of 26.4 months as compared to 22.3 months achieved in the 250 mg dose arm.
Mean Change in ER Expression Levels (Week 4)
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g2.gif

In preclinical mouse models, administration of 200 mg/kg of fulvestrant showed meaningful anti-tumor activity. However, based on recent published scientific literature, the human equivalent of the 200 mg/ kg dose of fulvestrant results in exposure that is an estimated eight-fold higher than what is clinically achievable with the highest FDA-approved human dose (500 mg) of fulvestrant. Based on these clinical and preclinical data, we believe the overall efficacy that can be achieved with the administration of fulvestrant may be capped by the current FDA-approved dose.
Convenience and resource utilization. The administration of fulvestrant as an intramuscular injection requires once monthly visits by patients to their health care providers, resulting in patient inconvenience and burden, such as time away from work. These injections also result in injection site pain, as well as bleeding complications in those patients with bleeding tendencies or anticoagulant use. In addition, significant injection related events such as sciatica, neuralgia, neuropathic pain, and peripheral neuropathy have been reported. Furthermore, we believe the combination of monthly intramuscular injections with a daily oral therapy, such as a CDK4/6 inhibitor, does not achieve optimal patient compliance.
SERD Use in Combination
Fulvestrant is FDA approved as a combination therapy with a number of other drug classes:
 
CDK4/6 inhibitors. One common mechanism of resistance to fulvestrant is the activation of the CDK4/6 pathway. Fulvestrant administered in combination with oral CDK4/6 inhibitors has demonstrated improved clinical efficacy when compared with fulvestrant as monotherapy. In a randomized, double-blind clinical trial, treatment of HR+/HER2- advanced breast cancer patients with a combination of fulvestrant and palbociclib demonstrated a median PFS of 9.5 months compared to 4.6 months for those patients dosed with fulvestrant as a single agent. These
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patients had previously progressed on or after prior endocrine therapy. Worldwide sales of currently marketed CDK4/6 inhibitors, which are indicated for the treatment of breast cancer, were $6.0 billion in 2019, and are expected to grow to $14.4 billion in 2026. Worldwide sales of Ibrance® were $5.0 billion in 2019 and are expected to grow to $9.7 billion in 2026.
Phosphoinositide 3-kinase, or PI3K, inhibitors. Another common mechanism of resistance to fulvestrant is the activation of the PI3K pathway, an important intracellular pathway that regulates cell growth and metabolism. Approximately one third of HR+ breast cancer tumors resistant to endocrine therapy harbor activating mutations of the catalytic subunit of PI3K, referred to as PIK3CA. Fulvestrant used in combination with alpelisib, an oral PI3K inhibitor marketed as Piqray® by Novartis approved by the FDA in May 2019, has demonstrated improved clinical efficacy in patients whose tumors had a PIK3CA mutation. In a randomized, double-blind clinical trial, treatment of HR+/HER2- advanced breast cancer patients with a PIK3CA mutation with a combination of fulvestrant and alpelisib led to a median PFS of 11.0 months compared to 5.7 months for those patients treated with fulvestrant as monotherapy. These patients had previously progressed on or after prior endocrine therapy. Worldwide sales of Piqray®, currently only FDA-approved for the treatment of breast cancer, were approximately $116.0 million in 2019 and are expected to grow to $1.4 billion in 2026.
Clinical data has also shown promising results from the use of fulvestrant with other targeted therapies:
 
Mammalian target of rapamycin, or mTOR, inhibitors. Similar to CDK4/6 and PI3K, the mTOR pathway has also been identified as a mechanism of resistance to endocrine therapy. Everolimus is an mTOR inhibitor that is currently approved by the FDA for the treatment of HR+/HER2- advanced breast cancer in combination with exemestane, an AI. Everolimus has also shown clinical benefit in combination with fulvestrant. In a randomized, double-blind clinical trial, treatment of HR+/HER2- advanced breast cancer patients with a combination of fulvestrant and everolimus demonstrated a median PFS of 10.3 months compared to 5.1 months for those patients dosed with fulvestrant as monotherapy. These patients had previously progressed on or after prior AI therapy. Worldwide sales in breast cancer of everolimus, marketed as Afinitor® by Novartis and a leading mTOR inhibitor, were approximately $831.0 million in 2019.

Our SERD Solution: ZN-c5
We believe a conveniently administered oral SERD with superior efficacy could be indicated for monotherapy or in combinations and could become the standard of care for hormonal therapy in the treatment of all lines of ER+/HER2- breast cancer.
ZN-c5 is our oral SERD product candidate, which we believe has the potential to overcome limitations of existing hormonal therapies in the treatment of ER+/HER2- breast cancer due to the following observed preclinical and clinical results:
 
Potency and selectivity. In our in vitro preclinical studies, we observed the potency of ZN-c5 as measured by proliferation inhibition and degradation of ERα, and that the combination of ZN-c5 and palbociclib was associated with meaningful shrinkage in MCF-7 tumors. In addition, ZN-c5 has exhibited no agonist activity in animal models which, if present, may compromise its anti-tumor activity.
Preclinical anti-tumor activity. In preclinical studies, ZN-c5 demonstrated anti-tumor activity in multiple breast cancer cell lines, both as monotherapy and in combination with CDK4/6 inhibitors and PI3Ka inhibitors, as well as superior tumor growth inhibition when compared to fulvestrant. In addition, in preclinical studies ZN-c5 demonstrated increased anti-tumor activity when administered in combination with BCL-2 inhibitors, including our BCL-2 inhibitor product candidate, ZN-d5, as compared to ZN-c5 as monotherapy.
Preliminary Clinical Activity As of the database cutoff date of June 30, 2020, one patient in the Phase 1, monotherapy dose expansion portion of the Phase 1/2 trial at the 150 mg/day dose level had met the definition of a confirmed partial response, or PR, per RECISTv1.1 criteria after four (4) cycles of ZN-c5. In addition, as of such date, six (6) of the 15 patients in the Phase 1, monotherapy dose escalation portion of the trial showed stable disease, or SD, for at least 24 weeks leading to a clinical benefit rate, or CBR, of 40%.
PK characteristics. In preclinical and clinical studies to date, oral dosing of ZN-c5 has shown high exposure levels.
Tolerability profile. In preclinical studies, ZN-c5 was well tolerated in one-month repeat dose toxicology studies. In addition, based on results from our Phase 1/2 clinical trial as of the database cutoff date of June 30, 2020, no dose-limiting toxicities have been reported.
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Safety profile. In clinical studies to date, ZN-c5 has demonstrated a favorable tolerability profile, which we believe may be an important differentiating factor for patients who require longer term dosing, particularly patients with earlier stage disease.
Convenience of administration. ZN-c5 was designed to be a once-daily oral drug. If approved, we believe this would provide patient convenience and the potential for an all oral dosing regimen as monotherapy and in combination with CDK4/6 inhibitors and other oral targeted therapies.
In our Phase 1/2 clinical trial, we are evaluating the potential of ZN-c5 as monotherapy and in combination with palbociclib, a CDK4/6 inhibitor, as part of a clinical development collaboration with Pfizer. In addition, we initiated a Phase 1b clinical trial evaluating ZN-c5 in combination with abemaciclib as part of a clinical collaboration with Lilly in November 2020, and we plan to initiate a Phase 2/3 clinical trial evaluating ZN-c5 in earlier stage breast cancer patients in 2021. We also intend to initiate a Phase 1b clinical trial evaluating ZN-c5 in combination with ZN-d5, our BCL-2 inhibitor product candidate, in patients with ER+/HER2- breast cancer in 2021.
Preclinical Results
Potency of ZN-c5 in Combination Therapy in MCF-7 Breast Cancer Xenograft Model
We have assessed the potency of the combination of ZN-c5 and palbociclib in mice with MCF-7 tumors. In this study, the tumors were initially grown to a large size of over 800 mm3, at which point treatment began on day 36. We observed that the combination of ZN-c5 and palbociclib, both dosed orally, led to the meaningful shrinkage of these tumors to a mean size of less than 200 mm3 by day 78, as shown in the graph below.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g3.gif
ER Degradation in MCF-7 Models
We assessed the potency of ZN-c5 and third-party hormonal therapies, fulvestrant and RAD1901, in repeat preclinical studies using MCF-7 breast cancer cells. RAD1901 is a SERM/SERD being evaluated by a third party in an ongoing Phase 3 clinical trial. As shown in the table below, ZN-c5 was observed to have good anti-proliferative activity and ERa degradation activity.
 
COMPOUND
PROLIFERATION
INHIBITION  IC50(1)(2)
MCF-7 (nM)
ERα
DEGRADATION
EC50(2)(3)
MCF-7 (nM)
Fulvestrant(4)
0.73 0.2 
RAD1901(4)
0.35 97 
ZN-c50.45 0.19 
(1)IC50: the concentration of an inhibitor where the response or binding is reduced by half.
(2)Data based on a series of repeat preclinical studies using standard in vitro assay and uniform controls.
(3)EC50: the concentration of a drug that gives half-maximal response.
(4)Data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than obtained from the pharmaceutical company commercializing or developing the respective hormonal therapy.
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Assessment of Agonist Activity
In preclinical studies, we observed no difference in agonist activity of ZN-c5 when compared to vehicle in a standard Uterine Wet Weight (UWW) animal model which, if present, may otherwise compromise anti-tumor activity.

Anti-tumor Activity in MCF-7 Breast Cancer Xenograft Models
In a preclinical study, we assessed the anti-tumor activity of ZN-c5, alongside fulvestrant and palbociclib, in each case as monotherapy, in multiple breast cancer cell lines. ZN-c5 was also assessed in combination with palbociclib. As shown in the graph below, in a xenograft model using human MCF-7 breast cancer cells, we observed that ZN-c5 dosed at 1 mg/kg had more potent anti-tumor activity than 200 mg/kg of fulvestrant. Even greater anti-tumor activity was observed by either increasing the dose of ZN-c5 to 40 mg/kg or by combination therapy using 5 mg/kg of ZN-c5 and 50 mg/kg of palbociclib.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g4.gif
(1)Fulvestrant data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company commercializing the compound.
Notes:
QW5:    Once per week (5 doses in 5 weeks)
QD:    Once daily

We also assessed the anti-tumor activity of ZN-c5, alongside fulvestrant and alpelisib, in each case as monotherapy, in preclinical models. ZN-c5 and fulvestrant were also assessed in combination with alpelisib. As shown in the graph below, in a xenograft model using human MCF-7 breast cancer cells, we observed that ZN-c5 dosed once daily at 1 mg/kg had more potent anti-tumor activity than 3 mg/dose of fulvestrant administered once per week over four (4) weeks. Even greater anti-tumor activity was observed with the combination of 1 mg/kg of ZN-c5 and 50 mg/kg of alpelisib. We also observed that the combination of ZN-c5 and alpelisib had more potent anti-tumor activity than the combination therapy using 3 mg/dose of fulvestrant and 50 mg/kg of alpelisib. In addition, the combination of ZN-c5 and alpelisib was associated with a body weight loss at the end of the study of 20.5% relative to baseline, compared to a body weight loss of 19% for alpelisib as monotherapy relative to baseline. The body weight loss at the end of the study for ZN-c5 as monotherapy was 7% relative to baseline.
 
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 https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g5.gif
(1)Data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company commercializing the compound.
Notes:
QW4:    once per week (4 doses in 4 weeks)
QD:    once daily

Anti-Tumor Activity in Breast Cancer Resistance Model (ESR1)
In a preclinical study, we assessed anti-tumor activity of ZN-c5 as monotherapy and in combinations with palbociclib and abemaciclib in animal models using patient-derived tumors, referred to as PDX models. We also assessed the anti-tumor activity of palbociclib, abemaciclib and fulvestrant each as monotherapy in the same PDX models. In the WHIM20 model, tumors were established in mice from a tumor isolated from a patient with metastatic breast cancer. This tumor contained a mutation in the ESR1, the gene encoding the ER. These mutations are a common mechanism that drives resistance to therapy, with a prevalence of resistance that ranges from 11% to 39%. As shown in the graph below, ZN-c5 was observed to have anti-tumor activity at a concentration of 40 mg/kg as a single agent in this model. As monotherapy, ZN-c5 demonstrated improved anti-tumor activity compared with the fulvestrant dose that results in exposure that is an estimated eight-fold higher than what is clinically achievable with the highest FDA-approved human dose of fulvestrant. Further, tumor shrinkage was observed with doses of 40 mg/kg ZN-c5 in combination with 50 mg/kg palbociclib and in combination with 50 mg/kg abemaciclib.
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https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g6.gif
(1)Data based on evaluation of comparable proxy chemical compounds purchased from commercial sources rather than the pharmaceutical companies commercializing the compound.
Notes:
QD:    once daily
QW12:    once per week (12 doses in 12 weeks)

Anti-Tumor Activity of ZN-c5 in Combination with BCL-2 Inhibitor in MCF-7 Breast Cancer Models
In preclinical studies, we assessed the anti-tumor activity of ZN-c5, both as monotherapy and in combination with ZN-d5, our BCL-2 inhibitor, as well as in combination with venetoclax. As shown in the graphs below, in MCF-7 breast cancer models, we observed that the combinations of ZN-c5 dosed at 10 mg/kg with venetoclax, dosed at 50 mg/kg, and ZN-d5, dosed at each of 50 mg/kg, 100 mg/kg and 200 mg/kg, had greater anti-tumor activity than 10 mg/kg of ZN-c5 as monotherapy.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g7.gif
(1)Venetoclax data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company commercializing the compound.
Notes:
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QD:     once daily
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g8.gif

PK Data Comparison in Mouse Model
We assessed the PK properties of ZN-c5 and select third-party hormonal therapies in clinical development in repeat preclinical mouse studies, as shown in the table below. Oral dosing of ZN-c5 resulted in peak concentrations, or Cmax, of 5,017 ng/mL. As shown below, ZN-c5 also had high overall drug exposure, or AUC, as measured by ng*hr/mL, and good oral bioavailability (F), which is the fraction of an oral administered drug that reaches systemic circulation
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g9.gif
(1)Based on oral administration.
(2)Data based on a series of repeat preclinical studies using standard in vitro assay and uniform controls.
(3)Other than H3B-6545, data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than obtained from the pharmaceutical company commercializing or developing the respective hormonal therapy. H3b-6545 data based on proxy chemical compound engineered based on published routes.

Toxicology Results
ZN-c5 was well tolerated in up to 28-day repeat dose toxicology studies and produced no evidence of diarrhea.
Phase 1/2 Clinical Trial of ZN-c5
Trial Design
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In December 2018, we initiated enrollment in our Phase 1/2 open label, multi-center trial of ZN-c5 in patients with ER+/HER2- advanced or metastatic breast cancer, which we refer to as our ZN-c5-001 Trial, to assess the safety, tolerability, PK, pharmacodynamics and anti-tumor activity of ZN-c5 as monotherapy and in combination with palbociclib. We plan to enroll a total of approximately 250 patients in the trial, which will be conducted at multiple sites in the United States and Europe.
The Phase 1 portion of our ZN-c5-001 Trial consists of: a monotherapy dose escalation study, a monotherapy expansion study and a combination dose escalation study evaluating ZN-c5 in combination with palbociclib. The Phase 2 portion will evaluate preliminary anti-tumor efficacy of ZN-c5 as monotherapy and in combination with palbociclib.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g10.jpg
 Phase 1, Monotherapy Dose Escalation
The primary objective of the Phase 1, monotherapy dose escalation portion of this trial is to determine the maximum tolerated dose, or MTD, and recommended Phase 2 dose, or RP2D. The secondary objectives include, among others, to assess the PK, safety and tolerability as well as preliminary efficacy of ZN-c5. In addition, biomarkers will be assessed based on availability of patients’ biopsies.
In the Phase 1, monotherapy dose escalation portion of this trial, ZN-c5 is being evaluated in up to 36 adult patients with ER+/HER2- advanced or metastatic breast cancer who are refractory to or intolerant of established cancer therapies, and who may have received up to two (2) prior chemotherapy regimens for advanced/metastatic breast cancer. ZN-c5 is being orally administered, either once or twice daily continuously at sequentially escalating doses starting with 50 mg/day and up to 1,200 mg/day, using a 28-day cycle.
Phase 1, Monotherapy Expansion
During the Phase 1, monotherapy dose escalation portion of the trial, up to 45 additional patients with ER+/ HER2- advanced or metastatic breast cancer who have received up to two (2) prior lines of endocrine therapy, and who have may have received at most one prior chemotherapy regimen for advanced/metastatic breast cancer, are expected to be enrolled onto one or more dose levels for the Phase 1, monotherapy expansion portion of this trial.

The primary objective of the Phase 1, monotherapy expansion portion of the trial will be to assess the safety and tolerability of ZN-c5 administered as monotherapy. Secondary objectives of the monotherapy expansion portion of this trial will include, among others, to assess the preliminary anti-tumor efficacy and characterize the PK of ZN-c5.
Phase 1, Combination Dose Escalation
We are also evaluating ZN-c5 in combination with palbociclib in the Phase 1, combination dose escalation portion of this trial in up to 40 adult patients with ER+/HER2- advanced or metastatic breast cancer who are refractory to or intolerant of established therapies known to provide clinical benefit for their malignancy, and who may have received at most one prior chemotherapy regimen for advanced metastatic breast cancer.
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The primary objective of the Phase 1, combination dose escalation portion of the trial is to determine the MTD or RP2D for ZN-c5 when administered in combination with palbociclib. Secondary objectives include, among others, to assess the safety and tolerability of ZN-c5 in combination with palbociclib, to assess preliminary efficacy of ZN-c5 in combination with palbociclib and to characterize the individual PK of ZN-c5 and palbociclib when administered in combination.
The dose and schedule of palbociclib in the Phase 1, combination dose escalation portion of this trial will be the FDA-approved dose (125 mg/day), orally administered, once daily for 21 consecutive days, followed by seven (7) days off treatment.
Phase 2
Once the MTD or RP2D have been determined for ZN-c5 as monotherapy and in combination with palbociclib, we plan to initiate enrollment in the Phase 2 portion of the trial to assess preliminary anti-tumor efficacy for ZN-c5 as monotherapy and in combination with palbociclib. We expect to initiate the Phase 2 monotherapy and combination portions of this Phase 1/2 trial in the first half of 2021.
The Phase 2 monotherapy portion of this trial will assess ZN-c5 at the RP2D in up to 75 adult patients with ER+/HER2- advanced breast cancer who have received one or two (2) prior lines of endocrine therapy, and no prior chemotherapy for advanced metastatic breast cancer.
The Phase 2 combination portion of this trial will evaluate ZN-c5 in combination with palbociclib in up to 112 adult patients with ER+/HER2- advanced or metastatic breast cancer and who have received up to one prior line of endocrine therapy, and at most one prior chemotherapy regimen for advanced metastatic breast cancer.
The primary objective of the Phase 2 portion of this trial will be to determine preliminary anti-tumor efficacy for ZN-c5 when administered as monotherapy and in combination with palbociclib. The secondary objectives will include, among others, to assess the safety and tolerability of ZN-c5 as monotherapy and in combination with palbociclib, and to characterize the PK of ZN-c5 as monotherapy and to characterize the individual PK of ZN-c5 and palbociclib when given in combination.
Clinical Results
As of June 30, 2020, we had enrolled 15 patients in the Phase 1, monotherapy dose escalation portion of this trial, three patients each at the dose levels of 50 mg, 75 mg, 100 mg, 150 mg and 300 mg. All patients were female, with a median age of 57 years (range 51 to 89 years) and an Eastern Cooperative Oncology Group, or ECOG, performance status, a measurement of a patient's level of functioning in terms of their ability to care for themself, daily activity, and physical ability, of 0 (n = 9) or 1 (n = 6).
The median number of prior therapies for advanced disease was four (4) (range two (2) to eight (8)). Twelve of the 15 patients received prior treatment with fulvestrant. Of these 15 patients, one is still on treatment and 14 discontinued due to disease progression (n = 13) or physician decision (n = 1). Enrollment in the Phase 1, monotherapy dose escalation portion of this trial has been completed.
As of June 30, 2020, 14 patients were enrolled in the Phase 1, monotherapy expansion portion of this trial, 12 patients at the 150 mg dose and two (2) patients at the 300 mg dose. All patients were female, with a median age of 57 years (range 38 to 73) and an ECOG performance status of 0 (n = 3) or 1 (n = 11). The median number of prior therapies for advanced disease was one (range zero (0) to three (3)). Six (6) of the 14 patients received prior treatment with fulvestrant. Of these 14 patients, five (5) are still on treatment and nine (9) discontinued due to disease progression. Enrollment in the Phase 1, monotherapy expansion portion of this trial has been completed.
As of June 30, 2020, we had enrolled 15 patients in the Phase 1, combination dose escalation portion of this trial, three patients each at the ZN-c5 dose levels of 50 mg and150 mg, and nine (9) patients at 100 mg. 14 patients were female and one was male, with a median age of 65 years (range 51 to 79 years) and an ECOG performance status of 0 (n = 7), 1 (n = 7) or 2 (n = 1). The median number of prior therapies for advanced disease was one (range zero (0) to six (6)). Three (3) of the 15 patients received prior treatments with fulvestrant. Of these 15 patients, nine (9) are still on treatment and six (6) discontinued due to disease progression (n = 5) and physician decision (n = 1). Enrollment in the Phase 1, combination dose escalation portion of this trial is ongoing and a total of up to 40 patients may be enrolled.
Safety Results
Phase 1, Monotherapy Dose Escalation and Monotherapy Dose Expansion
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Based on the results as of the database cutoff date of June 30, 2020 for the Phase 1, monotherapy dose escalation and monotherapy dose expansion portions of this trial, ZN-c5 has been observed to be well tolerated with no dose-limiting toxicities reported.
In the Phase 1 monotherapy dose escalation and monotherapy dose expansion portions of this trial, a total of 29 patients were enrolled and dosed, with data available in the electronic data capture system as of the June 30, 2020 database cutoff. Treatment-emergent adverse events, or TEAEs, occurred in 27 of the 29 patients. Nausea was observed in nine (9) patients; hyperglycemia in eight (8) patients; anemia, fatigue, hypertension and vomiting in six (6) patients each; headache in five (5) patients; cough, hot flush, hypokalemia, hypophosphatemia and lymphocyte count decreased in four (4) patients each; alanine aminotransferase, or ALT, increased, arthralgia, back pain, diarrhea, dyspnea, musculoskeletal pain and pyrexia in three patients each and all other adverse events were observed in only one or two (2) patients each. In addition, there have been no reports of bradycardia or any other cardiac abnormalities. TEAEs of Grade 3 severity were single cases of hypertension, hypercalcemia, back pain, arthralgia, pyrexia, COVID-19, device related infection, musculoskeletal chest pain, and pain in extremity. None of the Grade 3 TEAEs were deemed related to ZN-c5. All other TEAEs were of Grade 1 or Grade 2 in severity. The Grade 3 TEAEs of arthralgia, device related infection and COVID-19 were also reported as serious adverse events, all deemed unrelated to treatment. There were three serious adverse events reported; all deemed unrelated to treatment. There were no deaths reported.
Investigator assessed treatment-related adverse events occurred in 16 of 29 patients. These treatment-related adverse events included nausea, hot flush and fatigue (n = 3), ALT increased (n = 2) and other single adverse events. All were of Grade 1 or Grade 2 in severity.
Diarrhea, an adverse event of special interest, has been observed in three patients: one Grade 1 adverse event at 50 mg, which was deemed treatment-related; and one Grade 1 and one Grade 2 adverse event, each at 150 mg, neither of which was deemed treatment-related.
The first patient with ALT increased had the first dose of 50 mg of ZN-c5 on December 19, 2018. The patient entered the study with a Grade 1 ALT increased, which subsequently worsened to a Grade 2 ALT increased on February 13, 2019, 56 days after the first dose. On March 27, 2019, the patient was taken off treatment for disease progression, and at that time the Grade 2 ALT increased was still ongoing. The event was deemed related to ZN-c5. The second patient with ALT increased had the first dose of 300 mg of ZN-c5 on October 15, 2019. The patient developed Grade 1 ALT increased and Grade 1 aspartate aminotransferase, or AST, increased 84 days after the first dose, on January 6, 2020. Dosing was interrupted and the Grade 1 AST increased resolved on Day 91, and the Grade 1 ALT increased resolved on Day 98. The events were not deemed to be related to ZN-c5. The third patient with ALT increased had the first dose of 150 mg of ZN-c5 on December 18, 2019. The patient entered the study with Grade 1 ALT increased and AST increased, but AST increased normalized on Day 8 and ALT increased normalized on Day 15. The patient again developed Grade 1 ALT increased and Grade 1 AST increased 58 days after the first dose, on February 13, 2020. Dosing was not interrupted. The AST increased normalized on Day 83, but fluctuated again to Grade 1 on Day 162. On June 3, 2020, the patient was taken off treatment for disease progression, and at that time both the Grade 1 ALT increased and AST increased were still ongoing. The event was deemed to be related to ZN-c5.
Overall, in the Phase 1, monotherapy dose escalation and monotherapy dose expansion portions of the trial, there was no observed increase in severity of adverse events with increasing dosing levels.
Phase 1, Combination Dose Escalation
As of the June 30, 2020 database cutoff date, ZN-c5 in combination with palbociclib was observed to be well tolerated with no dose-limiting toxicities reported. Based on these safety results, we are continuing to enroll patients ZN-c5 in combination with palbociclib.
TEAEs occurred in 14 of the 15 patients dosed. Adverse events occurring in three or more patients included: white blood cell count decreased (n = 11); neutrophil count decreased (n = 9); anemia (n = 5), hyperglycemia, hypophosphatemia and nausea (n = 4); arthralgia, dizziness, fatigue, headache and platelet count decreased (n = 3). All other adverse events were observed in one or two (2) patients each. TEAEs of Grade 3 severity were neutrophil count decreased (n = 5), white blood cell count decreased (n = 3), arthralgia (n = 2) and single cases of each of hypophosphatemia, pneumothorax and pain in extremity. There was one serious adverse events of Grade 3 pneumothorax reported, deemed not related to ZN-c5 nor palbociclib.
Investigator assessed treatment-related adverse events to either ZN-c5 or palbociclib occurred in 13 of 15 patients. These investigator assessed treatment-related adverse events included: white blood cell count decreased (n = 11), neutrophil count decreased (n = 9), anemia (n = 5), fatigue (n = 3), platelet count decreased (n = 3), lymphocyte count decreased (n = 2) and
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other single adverse events. Events of Grade 3 severity were neutrophil count decreased (n = 3), and white blood cell count decreased (n = 5). Of note, there has been no evidence of any TEAEs of diarrhea bradycardia or visual disturbances. There were no deaths reported.
Overall, as of the June 30, 2020 database cutoff date, there was no increase in severity of adverse events observed with increasing dosing levels.
Efficacy Results
Clinical activity in the Phase 1 trial is determined by the CBR, which is the total number or percentage of patients who achieved a complete response, or CR, partial response, or PR, or stable disease, or SD, for 24 weeks or longer per RECIST v1.1 criteria.
While it is anticipated, based on the mechanism of action of ZN-c5 and advanced state of disease of the patients enrolled, that tumor regressions may not occur in this study phase, as of June 30, 2020, six (6) of the 15 patients in the Phase 1, monotherapy dose escalation portion of this trial showed SD for at least 24 weeks, leading to a CBR, of 40%. Two (2) of these patients were dosed at the low dose of 50 mg and showed SD for approximately 12 months.

Most patients in the combination dose escalation portion of the trial have been on treatment for less than 24 weeks, an insufficient amount of time to establish the CBR.

As of the database cutoff date of June 30, 2020, one patient in the Phase 1, monotherapy dose expansion portion of this trial at the 150 mg/day level has met the definition of a confirmed PR (reduction of 64%) per RECISTv1.1 criteria, starting after four (4) cycles of ZN-c5. Treatment of the patient is ongoing.

The following table illustrates treatment duration and best overall response for the Phase 1, monotherapy dose escalation portion of the trial as of the database cutoff date of June 30, 2020.

https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g11.gif
* Number of treatments reflect advanced or metastatic setting, not neo/adjuvant; also reflects combinations with targeted therapies CDK4/6, mTOR, PI3ka)
** P-palbociclib, A-abemaciclib, R-ribociclib; (E-experimental treatment)
SD: Stable Disease
PD: Progressive Disease
U: Unknown
ZN-c5 Pharmacokinetics Results
As of the database cutoff date of June 30, 2020, the PK of ZN-c5 observed in the first 15 patients in the Phase 1, monotherapy dose escalation portion of our ZN-c5-001 Trial was characterized by fast absorption into the systemic circulation, as evidenced by median time to maximum concentration, or Tmax, of one to two hours. As shown in the table below, the exposures have generally increased with increased doses and was 124,000 ng*hr/ml at the 300 mg dose. Additionally, we have not observed drug accumulation of ZN-c5 at steady state (Day 15). The estimated mean elimination half-life ranged between 11 and 18 hours.
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Preliminary Pharmacokinetic Data for ZN-c5 Monotherapy
 
Dose (mg)
# of pts
Day 1Day 15Day 15/Day 1 AUC Ratio
Cmax
(ng/mL)
Tmax
(hr)
AUC0-24hr (ng*h/mL)
Cmax
(ng/mL)
Tmax
(hr)
AUC0-24hr (ng*h/mL)
50Mean5,730265,7005,810161,3000.94
(n=3)SD1,330(1-2)7,350405(1-2)10,4000.20
CV (%)23.311.26.9717.021.4
75Mean6,700277,3006,700264,4001.1
(n=3)SD4,080(1-4)47,8001,040(1-2)16,0000.66
CV (%)60.861.915.624.859.8
100Mean7,1204103,0009,2502106,0000.97
(n=3)SD2,550(2-6)42,1005,350(1-2)74,5000.30
CV (%)35.940.757.870.231.6
150Mean8,1202115,0009,210294,8000.83
(n=3)SD1,780(2-4)42,2002,820(1-2)41,6000.20
CV (%)21.936.730.643.924.8
300Mean10,7006168,00010,0002124,0000.74
(n=3)SD1,390(2-6)21,4001,170(2-6)21,3000.07
CV (%)13.012.711.717.29.15
Median (range) are listed for Tmax
SD:     standard deviation
ZN-c5 human drug exposure at all dose levels, ranging from 50 mg to 300 mg, exceeds the ZN-c5 effective concentration, 100%, or EC100, observed in our preclinical mouse studies at 10 mg/kg/day, the dose level associated with a 100% tumor growth inhibition in an MCF-7 mouse model. Based on the activity observed in mouse models, the exposures observed in human patients may translate into once daily, oral dosing.
Phase 1 Trial of ZN-c5 (Window of Opportunity study)
In January 2020, we dosed the first patient in our Phase 1 open label, multi-center, dose escalation trial of ZN-c5, which we refer to as our ZN-c5-002 Trial. The ZN-c5-002 Trial will be conducted at several sites in the United States, Europe and Asia-Pacific (Australia), in patients with ER+/HER2- breast cancer scheduled to undergo surgical resection of the tumor or start neoadjuvant treatment. We plan to enroll approximately 36 patients in this trial.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g12.gif
This is a Window of Opportunity study, the objective of which is to assess the ER degradation ability of ZN-c5 as a monotherapy over a 21-day treatment period measured using paired biopsies. We intend to evaluate various tissue and functional imaging biomarkers in response to ZN-c5 exposure. These biomarkers will assess ER degradation, progesterone receptor degradation and Ki67, a proliferation marker, using paired biopsies. In addition, tumor tissue and plasma concentration of ZN-c5 will be assessed.
ZN-c5 will be evaluated at escalating doses starting at 50 mg, orally administered, once daily. Subsequent dose levels will be determined based on PK profile, safety and any additional biomarker data observed in our ZN-c5-001 Trial.
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At June 30, 2020, eight patients had been enrolled and treated: three patients at 50 mg/day, four (4) patients at 150 mg/day and one (1) patient at 300 mg/day.
We believe this trial will assist in determining the precise RP2D of ZN-c5 as a monotherapy, in conjunction with the safety, PK and pharmacodynamics, or PD, data from the ZN-c5-001 Trial. We expect to report topline results from this trial in the first half of 2021.
Phase 1b Trial of ZN-c5 in combination with abemaciclib
In November 2020, we dosed the first patient in our Phase 1b open label, multi-center trial of ZN-c5 in combination with abemaciclib in patients with ER+/HER2- advanced or metastatic breast cancer, which we refer to as our ZN-c5-003 Trial. This trial aims to assess the safety, tolerability, PK, pharmacodynamics, and anti-tumor activity of ZN-c5 in combination with abemaciclib. The ZN-c5-003 Trial will be conducted at several sites in the United States and Europe. We plan to enroll approximately 18 patients in this trial.

ZN-c3, an Inhibitor of WEE1 for the Treatment of Solid Tumors and Other Cancers
Overview
We are developing ZN-c3, an oral, small molecule DNA damage response product candidate, targeting WEE1 in cancer. The inhibition of WEE1, a protein tyrosine kinase, aims to generate sufficient DNA damage in cancer cells to undergo apoptosis, thereby preventing tumor growth and potentially causing tumor regression. There is currently no FDA-approved WEE1 inhibitor, and AstraZeneca’s AZD1775 is currently one of few other WEE1 inhibitors in clinical development of which we are aware. Despite the observed efficacy of AZD1775 in clinical trials, we believe its narrow therapeutic window is a potential limitation affecting its dosing in monotherapy and in combination. We have applied our expertise to design ZN-c3 to have such solubility, selectivity and PK properties that we believe may provide a broad therapeutic window and which, if ZN-c3 is approved, may constitute a differentiated product profile. We believe ZN-c3, if approved, may have broad applicability in a wide range of cancers both as monotherapy and in combination, including with chemotherapy agents, PARP inhibitors and other targeted therapies.
We have initiated a Phase 1/2 clinical trial of ZN-c3 in patients with advanced solid tumors. We plan to report results from the Phase 1, monotherapy dose escalation portion of the trial at the AACR Annual Meeting in April 2021. In addition, we initiated a Phase 1b clinical trial evaluating ZN-c3 in combination with chemotherapy in patients with advanced ovarian cancer in October 2020, and plan to initiate a Phase 2 trial evaluating ZN-c3 as monotherapy in patients with USC in 2021. We continue to actively evaluate other potential combinations for the future clinical development of ZN-c3, and intend to initiate two (2) additional Phase 1 clinical trials evaluating ZN-c3 in combination with chemotherapy and PARP inhibitor in ovarian cancer and other targeted indications in 2021.
Background on DNA Damage Repair and WEE1 Inhibitors
The underlying principle behind a number of cancer therapies is to generate sufficient DNA damage in cancer cells, many of which already have deficiencies in DNA damage response, to cause them to undergo apoptosis. Examples of these therapies include alkylating agents, DNA-binding drugs and the use of radiation. However, cancer cells have developed multiple mechanisms of resistance to these therapies, thereby potentially limiting their therapeutic efficacy.
The regulation of DNA damage response mechanisms in cancer cells may therefore play a crucial role in the induction of apoptosis and the ultimate efficacy of DNA damaging cancer therapies. This is particularly true in cancers with specific mutations in DNA repair proteins that prevent efficient DNA damage response and repair, rendering them particularly vulnerable to any agent that further inhibits the ability of cells to repair DNA damage.
Examples of such cancers are those with mutations in BRCA1 and BRCA2. Inhibitors of PARP, an independent DNA repair protein, work to prevent DNA damage repair, and are FDA approved for the treatment of multiple cancers, such as breast and ovarian cancers associated with BRCA1 and BCRA2 mutations. Sales of FDA-approved PARP inhibitors were approximately $1.6 billion in 2019 and are expected to grow to $6.9 billion in 2026.
Similar to PARP, WEE1 plays a role in cellular regulation and repair, allowing cells with DNA damage to repair and survive. WEE1 is a protein tyrosine kinase that mediates cell cycle arrest by regulating the phosphorylation of cyclin-dependent
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kinase 1, or CDK1. Inhibition of WEE1 causes dysregulation of DNA replication and inability of DNA response processes to act, leading to an increase in double-strand DNA breaks and subsequently inducing apoptosis. Based on these similar mechanisms of action, we believe the use of WEE1 and PARP, both DNA damage response agents, in combination can have a synergistic effect. In third-party preclinical studies, the combination of PARP and WEE1 has been observed to result in improved anti-tumor activity as compared to the use of each as monotherapy. However, both of these compounds have been associated with bone marrow toxicity, which may limit their concomitant administration.
WEE1 Inhibitor in Clinical Development and Limitations
One of few other WEE1 inhibitors currently in clinical development of which we are aware is AZD1775. AZD1775 has been the subject of many publications in the scientific literature and has been explored in numerous clinical trials across multiple tumor types. AZD1775 is currently being evaluated by third parties in Phase 1 and 2 clinical trials in ovarian cancer and a variety of other solid tumors, both as monotherapy and in combination with other cancer therapies. In earlier third-party clinical trials, multiple patients with advanced or metastatic tumors for whom no standard therapy was available achieved partial responses when dosed with AZD1775 in combination with chemotherapy agents. For example, in a Phase 2 clinical trial in 24 patients (21 of such patients were evaluable for efficacy) with relapsed ovarian cancer, the combination of AZD1775 and carboplatin, an FDA-approved chemotherapy, demonstrated an overall response rate of 43% and one patient exhibited a complete response lasting over 42 months.
In addition, in a recent Phase 2 clinical trial in patients with recurrent USC, an aggressive subtype of endometrial carcinoma characterized by TP53 mutations, AZD1775 administered as monotherapy demonstrated an overall response rate of 30%.
Further, in a recent Phase 1 clinical trial in patients with locally advanced pancreatic cancer, AZD1775 in combination with gemcitabine, an FDA-approved chemotherapy, and radiation resulted in a median overall survival of 21.7 months. This overall survival was substantially longer than the 11.9 to 13.6 months observed in a prior clinical trial with a similar population of patients combining gemcitabine with or without erlotinib with radiation.
Although AZD1775 has demonstrated promising efficacy in clinical trials, we believe AZD1775 has a narrow therapeutic window, a potential limitation affecting its dosing as monotherapy and in combination. Furthermore, the use of AZD1775 in combination with PARP inhibitors in preclinical studies has demonstrated increased bone marrow toxicities, thereby potentially limiting its use in continuous dosing. We believe AZD1775 has a number of characteristics that could be improved upon, including selectivity, solubility, PK properties and tumor concentration.
Our WEE1 Solution: ZN-c3
ZN-c3 is our oral WEE1 inhibitor product candidate that we are currently evaluating for the treatment of advanced solid tumors in an ongoing Phase 1/2 clinical trial. We believe ZN-c3 has the potential to provide a wide therapeutic window due to the following observed clinical and preclinical results:
 
Potency, selectivity and solubility. In our preclinical studies, ZN-c3 produced favorable absorption, distribution, metabolism and excretion, or ADME, results. In our in vitro preclinical studies, we observed ZN-c3’s potency in inhibiting tumor growth and inducing apoptosis through DNA damage, and ZN-c3 has shown high selectivity for WEE1. In addition, in a series of repeat preclinical studies assessing the solubility of ZN-c3 and AZD1775 utilizing a standard in vitro assay and uniform controls, ZN-c3 demonstrated solubility of 2,132,000 nM, approximately 35 times greater than that of AZD1775, which we believe could reduce inter-patient drug exposure variability and limit the toxicity observed in clinical trials of AZD1775.
Preclinical anti-tumor activity. In head-to-head preclinical studies, ZN-c3 showed anti-tumor activity across a number of cell lines, as well as superior tumor growth inhibition, DNA damage and apoptosis when compared to AZD1775. Anti-tumor activity was observed in both continuous and intermittent dosing, as well as in the shorter of the dosing periods evaluated.
PK properties. In our preclinical studies, ZN-c3 showed PK properties that resulted in high drug exposure in animal models. We believe this level of drug exposure may contribute to the observed sustained and lengthy tumor growth inhibition, which may necessitate lower dose intensity thereby potentially affording a wide therapeutic window. In addition, we observed that ZN-c3 had favorable drug accumulation in tumors.
Well tolerated in preclinical studies and clinical trials. In preclinical studies and clinical trials to date, ZN-c3 was observed to be well tolerated across varying dosage levels.
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In addition to having a potentially wide therapeutic window, we believe the characteristics of ZN-c3 may allow patients with aggressive solid tumors to be treated with sequential therapy using mechanism of action synergistic multiple agents, including PARP inhibitors. In a third-party preclinical combination study with PARP inhibitors, sequential dosing resulted in favorable tolerability as compared to continuous dosing, while maintaining strong anti-tumor activity.
We have completed the dose escalation part of our Phase 1 monotherapy study, and we plan to report data from the dose escalation portion of the trial at the AACR Annual Meeting in April 2021.
Preclinical Results
Potency Across Variety of Solid Tumor Cell Lines
We assessed the potency of ZN-c3 and AZD1775 in repeat in vitro preclinical studies across a variety of solid tumor cell lines, as shown in the table below. We observed ZN-c3’s potency in inhibiting tumor growth and inducing DNA damage and apoptosis in each of the solid tumor cell lines studied.
 
 
CTG IC50 (nM)(1)
 Non-Small Cell
Lung Cancer
Small Cell Lung
Cancer
Triple Negative
Breast Cancer
Ovarian CancerSquamous
Cell
Carcinoma
COMPOUNDA-427NCI-H23DMS-53NCI-H1048MDA-MB-231HCC1806UWB.1.289OVCAR3SK-MES-1
AZD1775(2)
94 108 130 97 233 94 57 124 150 
ZN-c388 124 118 92 190 95 54 69 83 
(1)Data based on a series of repeat preclinical studies using standard in vitro assay and uniform controls.
(2)Data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company developing the compound.

Selectivity of ZN-c3 in Kinase Screening Panel
In our head-to-head in vitro preclinical studies, we assessed the selectivity of ZN-c3, alongside AZD1775. The selectivity profile of each of ZN-c3 (right) and AZD1775 (left) was characterized against a broad kinase panel for WEE1 consisting of 485 mammalian serine/threonine and tyrosine, as depicted by the respective kinase dendograms below. ZN-c3 and AZD1775 were tested at a single concentration to determine the percentage inhibition at 1 μM. ZN-c3 was observed to have higher selectivity relative to that of AZD1775 as depicted by the overall fewer kinases being affected in the ZN-c3 dendogram.

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https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g13.jpg
Notes:
Illustration reproduced courtesy of Cell Signaling Technology, Inc. Each branch of the dendogram represents an individual human kinase. AZD1775 data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company developing the compound.
Solubility of ZN-c3
We assessed the relative ADME properties and solubility of ZN-c3 and a proxy chemical compound of AZD1775 in a series of repeat preclinical studies. ZN-c3 showed targeted ADME properties, and demonstrated solubility of 2,132 µM, approximately 35 times greater than the 60 µM observed with AZD1775 in repeat preclinical studies. We believe greater solubility may reduce interpatient variability, and in turn limit toxicities for ZN-c3.

Anti-Tumor Activity in Human Lung Cancer Model
In a preclinical study, we assessed the anti-tumor potential of ZN-c3 alongside AZD1775, each as a monotherapy, in a lung cancer model using human A-427 cells that contained a KRAS mutation. In this model, doses of 40 mg/kg or 80 mg/kg of ZN-c3 demonstrated tumor shrinkage that was evident at the first post-treatment observation at four (4) days and continued through the end of the experiment. Across dose levels there was no statistical difference between ZN-c3 and AZD1775 and each compound produced tumor regression. ZN-c3 was observed to be well tolerated across all doses.
 
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 https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g14.gif
(1)AZD1775 data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company developing the compound.
Notes:
QD:    once daily

Anti-Tumor Activity in Lung Cancer Model Across Varying Dosage Levels and Intermittent Dosing Regimen
We have explored various dosing regimens of ZN-c3 in preclinical studies. A loading dose of 120 mg/kg daily for seven (7) days followed by once-daily dosing of 100 mg/kg resulted in ten (10) out of ten (10) treated mice being tumor free after five (5) weeks. We also explored the potential of shorter dosing periods or intermittent dosing of ZN-c3 in preclinical studies. A loading dose of 120 mg/kg for five (5) days followed by two (2) days off drug followed by five (5) weeks of 100 mg/kg given five (5) days on, two (2) days off resulted in seven (7) out of ten (10) mice being tumor free as shown in the graph below. A loading dose of 120 mg/kg for seven (7) days followed by seven (7) days off drug followed by two cycles of seven (7) days on 100 mg/kg drug and seven (7) days off drug resulted in five (5) out of ten (10) mice being tumor free as shown in the graph below.

 https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g15.gif
We also assessed the potential of utilizing an intermittent dosing regimen with ZN-c3 alongside that of AZD1775 in a preclinical study. Dosing of ZN-c3 by using a loading dose of 120 mg/kg for four (4) days followed by three days off drug
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followed by five (5) weeks of 100 mg/kg given four (4) days on, three (3) days off resulted in more prolonged tumor growth delay than that observed with AZD1775 at the same dosing regimen.


https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g16.gif




PK Data Comparison in Animal Models
We assessed the PK properties of ZN-c3 and AZD1775 in repeat preclinical animal models, as shown in the table below. For each of the preclinical studies, we observed the respective Cmax, Tmax, AUC and tumor concentration of each compound at doses of 20, 40 and 80 mg/kg/day. Administration of ZN-c3 was observed to result in high drug exposure in animal models and the selective accumulation of ZN-c3 to high levels in tumors. We believe this increased drug exposure may cause the inhibition of WEE1 at low doses, potentially affording a wide therapeutic window.
 
STUDY(1)
ZN-c3
AZD1775(2)
Dose (mg/kg/day)20 40 80 20 40 80 
Cmax (ng/mL)
1,167 1,997 5,100 635 2,460 4,703 
Tmax (hr)
AUC0-24hr (ng*hr/mL)
4,863 17,088 39,722 1,494 6,313 13,408 
Tumor Concentration (ng/mL)10.5 48.0 811 BQLBQL6.95 
(1)Data based on a series of repeat preclinical studies using standard assay and uniform controls.
(2)Data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than obtained from the pharmaceutical company developing the compound.
Note:
BQL:    Below Quantifiable Level

Toxicology Results
ZN-c3 was evaluated in 28-day repeat dose toxicology studies. Results of these studies showed many of the toxicities associated with other WEE1 inhibitors in development, including those reported for AZD1775.
Phase 1/2 Clinical Trial of ZN-c3
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In November 2019, we initiated a Phase 1/2 open label, multi-center trial of ZN-c3 in patients with advanced solid tumors, which we refer to as our ZN-c3-001 Trial, to assess the safety, tolerability, efficacy, PK properties and pharmacodynamics of ZN-c3 as a single agent and in combination with a number of potential therapies, including PARP inhibitor. We plan to enroll up to 360 patients in this trial, which is being conducted at several sites in the United States. Our ZN-c3-001 Trial currently consists of a monotherapy dose escalation portion of the trial and a dose expansion portion to evaluate ZN-c3 as monotherapy and in combination with relevant combination therapies.
The primary objective of the Phase 1, monotherapy dose escalation portion of the trial is to assess the safety and tolerability of ZN-c3 as a single agent and to determine the MTD or RP2D. The secondary objectives are to assess the PK properties and obtain preliminary assessments of anti-tumor efficacy of ZN-c3 as a single agent, as well as exploratory PD characteristics.
We plan to enroll up to 70 patients in the Phase 1, monotherapy trial and the patient population will be limited to patients with solid tumors with advanced or metastatic disease who are refractory or ineligible to receive standard therapies, or for whom no standard therapy is available. We expect to report topline results from the Phase 1, monotherapy dose escalation portion of this trial in 2021.
The primary objective of the dose expansion portion of the trial will be to assess the anti-tumor efficacy of ZN-c3 by objective response rate at the RP2D. The secondary objectives of the dose expansion portion will be to assess the anti-tumor efficacy of ZN-c3 by duration of response, clinical benefit rate and PFS as monotherapy, and to assess the PK parameters of ZN-c3.
Phase 1b Clinical Trial of ZN-c3
We initiated a Phase 1b, combination dose escalation clinical trial evaluating ZN-c3 in combination with chemotherapy in patients with advanced ovarian cancer in October 2020.
The primary objective of this Phase 1b, combination dose escalation trial is to determine the MTD or RP2D for ZN-c3 when administered in combination with chemotherapy.
 

ZN-c3 Clinical Program
 https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g17.jpg
Interim Clinical Results
Interim data is subject to change as more data on these patients and additional patients become available and are subject to audit and verification procedures that could result in material changes in the final data.
Safety Results
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As of the June 19, 2020 database cutoff, in the Phase 1, monotherapy dose escalation portion of the ongoing ZN-c3-001 trial, a total of 22 patients were enrolled and dosed and had data available in the electronic data capture system: two (2) patients each at the dose levels of 25 mg, 50 mg, 200 mg and 300 mg, four (4) patients at 100 mg and ten (10) patients at 75 mg/day. Enrollment in the Phase 1, monotherapy dose escalation portion of this trial is ongoing, and a total of up to 50 patients may be enrolled.
As of the June 19, 2020 database cutoff, no dose limiting toxicities were observed. TEAEs occurred in 21 of the 22 patients. Nausea was observed in seven (7) patients; diarrhea in six (6) patients; fatigue in five (5) patients; anemia in four (4) patients; and abdominal distention, decreased appetite, dyspnea, gamma-glutamyltransferase increased, pyrexia and vomiting in three patients each. All other adverse events were observed in one or two (2) patients each. A single TEAE of Grade 4 severity (ALT increased) was observed. TEAEs of Grade 3 severity included two (2) cases of gamma-glutamyltransferase increased, and single cases of anemia, hepatic enzyme increased, blood bilirubin increased, hypertension, sepsis, and AST increased. All other TEAEs were of Grade 1 or Grade 2 in severity. The Grade 3 TEAEs of sepsis, anemia (n = 2) and hepatic enzyme increase also accounted for four (4) of the six (6) serious adverse events reported. The other two serious adverse events included Grade 2 transient ischemic attack and large intestinal obstruction. No serious adverse event was deemed related to ZN-c3. There were no deaths reported.
Investigator assessed treatment-related adverse events occurred in 14 of 22 patients. These treatment-related adverse events included diarrhea and nausea in three patients each, fatigue and vomiting in two (2) patients each, and other single adverse events. A single treatment-related adverse event of Grade 4 severity (ALT increased) was observed. Grade 3 treatment-related adverse events reported included AST increased and hepatic enzyme increased. All others were of Grade 1 or Grade 2 in severity. None of the liver function test abnormalities were indicative of drug-induced liver injury. Of the two (2) patients with treatment-related hepatic enzyme increased, one had a history of ethanol use.
Overall, as of the June 19, 2020 database cutoff date, there was no increase in incidence or in severity of adverse events observed with increasing dosing levels.
The following graphs show hematological parameters (neutrophilis, platelets or hemoglobin) on study for individual patients in each of the higher dose groups (100 mg/day, 200 mg/day and 300 mg/day). As of the June 19, 2020 database cutoff date, we have observed higher exposures with escalating doses of ZN-c3. Of note, these exposures have not led to a negative effect on hematological parameters (neutrophilis, platelets or hemoglobin).

ZN-c3-001 – Hematology – Neutrophils
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g18.gif
Notes:
QD: once daily

ZN-c3-001 – Hematology – Platelets
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https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g19.gif
Notes:
QD: once daily

ZN-c3-001 – Hematology – Hemoglobin

https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g20.gif
Notes:
QD: once daily
ZN-c3 Pharmacokinetics Results
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As of the June 19, 2020 database cutoff date, upon oral dosing at the dose levels of 25 mg to 200 mg, ZN-c3 was absorbed into the systemic circulation with the median Tmax of one (1) to four (4) hours and the typical half-life was six (6) to nine (9) hours. As shown in the table below, Cmax and AUC values of ZN-c3 increased in an approximately dose proportional manner on Day 1 and greater than dose proportionally on Day 15. Based on AUC, there was low to no ZN-c3 accumulation on Day 15 compared to Day 1, with accumulation ratios ranging between 0.72- and 2.38-fold.

Preliminary Pharmacokinetic Data for ZN-c3
Dose (mg)Day 1Day 15
Cmax
(ng/mL)
Tmax
(hr)
AUC0-24hr (ng*h/mL)
Cmax
(ng/mL)
Tmax
(hr)
AUC0-24hr (ng*h/mL)
Accumulation by AUClast
25Mean14.3287.29.14262.7~0.72
50Mean54.62.553347.845941.12
75Mean12221,10015211,3301.67
SD98.7(1-4)1,00070.5(0-24)3780.75
CV80.890.646.328.544.8
100Mean12411,12019931,6201.56
SD118(1-24)827285(1-24)1,7500.78
CV95.274.014410850.0
200Mean3532.02,87071226,1602.38
SD327(1-4)1,950464(1-2)3,2500.53
CV92.668.165.252.822.4
Notes:
Median (range) are listed for Tmax
25 and 50 mg: n = 2; 75 mg: n =10 on Day 1 and n = 8 on Day 15; 100 mg: n = 4; 200 mg: n = 3
Data regarding clinical activity are premature at this point. Pharmacodynamic data will be collected in subsequent patients and will be reported in the future.
ZN-d5, an Inhibitor of BCL-2 for the Treatment of Hematologic Cancers
Overview
We are developing ZN-d5, an oral selective inhibitor of BCL-2, an intracellular protein that suppresses apoptosis for the treatment of cancers, with an initial focus on hematologic malignancies. We have applied our expertise to design ZN-d5 as an oral BCL-2 inhibitor and to have optimized potency, selectivity and PK.
We began enrolling subjects in a Phase 1 clinical trial evaluating ZN-d5 in patients with relapsed or refractory NHL and AML, in October 2020. This trial is initially enrolling subjects with NHL and we expect to open enrollment to subjects with AML in 2021. This dose-escalation study is designed to assess the safety, efficacy and PK of ZN-d5, and to determine the MTD and RP2D in NHL and AML. In 2021, we intend to initiate a Phase 1/2 clinical trial evaluating ZN-d5 as monotherapy and Phase 1b clinical trial in combination with ZN-c5, our oral SERD product candidate, in patients with ER+/HER2- breast cancer.
Role of BCL-2 in Hematological Cancers
The BCL-2 family of protein is most notable for its critical role in the regulation of apoptosis at the mitochondrion. Based upon their functions, BCL-2 family proteins are classified into pro-apoptotic and anti-apoptotic members. The anti-apoptotic BCL-2 proteins include BCL-2, B-cell lymphoma extra-large, or BCL-xL, myeloid cell leukemia-1, or MCL-1, and BCL-2 related protein Al.
The overexpression of BCL-2 and/or BCL-xL proteins is frequently detected in many different types of cancers, including chronic lymphatic leukemia, or CLL, SLL, AML, NHL (including follicular lymphoma, or FL, mantle-cell lymphoma, or MCL, diffuse large B-cell lymphoma, or DLBCL),Waldenström’s macroglobulinemia, multiple myeloma, or MM, and small cell lung cancer, or SCLC. These overexpressed proteins prevent apoptosis of cancer cells. We believe the use of small molecule inhibitors to block the protein-protein interactions of BCL-2 and/or BCL-xL with their pro-apoptotic partners will restore the normal apoptosis process in cancer cells. This new cancer therapeutic strategy has been validated through the recent approval of Venetoclax as described below.
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There have been many attempts to develop a new class of anticancer therapies that target BCL-2 and/or BCL-xL proteins. The intracellular localization of the BCL-2 family proteins on the mitochondrial membrane prevents the use of antibodies and other large molecules to target these anti-apoptotic BCL-2 family proteins. The large surface area involved in BCL-2 PPIs also makes BCL-2 family proteins difficult targets for small molecule drugs. Currently, venetoclax is the only FDA-approved BCL-2 inhibitor and, to our knowledge, there are only a small number of additional agents in active clinical development.
FDA-Approved BCL-2 Inhibitor, Venetoclax
Venetoclax, the only FDA-approved BCL-2 inhibitor (marketed by AbbVie and Genentech as Venclexta®), was initially developed to overcome unfavorable side effects of previously tested BCL-2 inhibitors resulting from BCL-xL inhibition, which is known to cause thrombocytopenia. Venetoclax has demonstrated clinical efficacy across a range of hematological malignancies and is now FDA-approved for the treatment of adult patients with CLL and SCC, and in combination with azacitidine, or decitabine, or low-dose cytarabine for the treatment of newly diagnosed AML in adults 75 years of age or older, or who have comorbidities that preclude use of intensive induction chemotherapy. Common adverse reactions for Venclexta in CLL/SLL include neutropenia, thrombocytopenia, anemia, diarrhea, nausea, upper respiratory tract infection, cough, musculoskeletal pain, fatigue, and edema, and in AML include nausea, diarrhea, thrombocytopenia, constipation, neutropenia, febrile neutropenia, fatigue, vomiting, edema, pyrexia, pneumonia, dyspnea, hemorrhage, anemia, rash, abdominal pain, sepsis, musculoskeletal pain, dizziness, cough, oropharyngeal pain, and hypotension (source: Venclexta prescribing information, February 18, 2021).
Promising results for venetoclax have been reported in a variety of other hematologic malignancies as monotherapy and in combination with other targeted agents as well as traditional cytotoxic chemotherapy. Worldwide sales of Venclexta® were approximately $1.3 billion in 2020, an increase of 69% from 2019.
Emerging Role of BCL-2 in Solid Tumors
Although the development of venetoclax has to date been primarily limited to hematologic cancers, a study in a panel of cell lines derived from a variety of tumors demonstrated that BCL-2 expression and venetoclax sensitivity has been observed in multiple solid tumors. These include SCLC, bone, breast, and nervous system tumors. A clinical trial of venetoclax in combination with tamoxifen in patients with ER+/BCL-2+ metastatic breast cancer showed a 54% response rate and clinical benefit rate of 75%, providing clinical evidence that BCL-2 inhibition is a viable target in solid tumors (source: Lok et al., Cancer Discovery 2019; 9:354-369. https://doi.org/10.1158/2159-8290.CD-18-1151).
Additionally, the efficacy of venetoclax used in combination with fulvestrant versus fulvestrant administered as monotherapy is being evaluated in an ongoing third-party Phase 2 clinical trial in patients with ER+/HER2- breast cancer.
Our BCL-2 Inhibitor: ZN-d5
ZN-d5 is our oral, small molecule BCL-2 inhibitor product candidate for the treatment of cancers, with the initial focus on hematologic malignancies. We have designed ZN-d5 to have the following characteristics:
 
Potency. In our preclinical studies, ZN-d5 was observed to be potent in cell lines and xenograft models across a variety of hematological malignancies.
Selectivity. In our in vitro studies, ZN-d5 showed more than 600 times greater selectivity for BCL-2 than BCL-xL. The inhibition of BCL-xL is a known cause of thrombocytopenia, a commonly reported toxicity in patients treated with venetoclax. We believe ZN-d5's greater selectivity for BCL-2 over BCL-xL observed in preclinical studies may support the use of ZN-d5 in combination with other drugs that are associated with a high rate of thrombocytopenia.
Tolerability profile. In our animal toxicity studies, ZN-d5 was observed to be well tolerated across various dosage levels.
We believe the observed properties of ZN-d5 make it an attractive candidate for evaluation as monotherapy and in combination with other therapies, initially for the treatment of hematological malignancies. As noted above, ZN-d5 entered clinical trials in the third quarter of 2020 in a Phase 1 dose escalation study that is currently enrolling NHL patients. Our plans for 2021 for ZN-d5 include opening enrollment in the ongoing study to patients with AML and launching a Phase 1b trial in combination with ZN-c5, our oral SERD product candidate, in patients with ER+/HER2- breast cancer in 2021.
Preclinical Results
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Potency and Selectivity Across Hematological Malignancies
In an in vitro preclinical study, we assessed the selectivity and potency of ZN-d5 alongside venetoclax. As shown in the table below, we assessed the affinity of each agent as measured in nM in a biochemical assay. Based on these measurements, ZN-d5 showed 600 times greater selectivity for BCL-2 than BCL-xL, and we believe such selectivity may limit the incidence of thrombocytopenia observed in third-party clinical trials as a result of BCL-xL inhibition. We also observed that ZN-d5 was potent across hematological malignancy cell lines as measured by CellTiter-Glo, or CTG, a cell viability assay, shown in the table below.
 
 
CTG IC50 (nM)
 AFFINITY (nM)ALLMCLDLBCLAML
COMPOUNDBCL-2
Kd
BCL-XL
Kd
RS4;11GRANTA-
519
DOHH-2TOLEDOHL-60MOLM-
13
MV4-11
Venetoclax(1)
0.41 28 2.9 161 43 191 26 18 3.8 
ZN-d50.29 190 5.1 89 50 92 21 39 5.1 
(1)Data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company commercializing the compound.

In a preclinical study, we also assessed the platelet toxicity of ZN-d5 against venetoclax, as measured by mM in a platelet viability assay. In each assay, ZN-d5 was observed to be less toxic to platelets than venetoclax, which we believe may limit the incidence of thrombocytopenia.

https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g21.gif
(1)Data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company commercializing the compound.
Potency for BCL-2 Mutations
We believe genetic mutations in the BCL-2 gene may be responsible for a developed resistance to venetoclax observed in some CLL patients. In a third-party clinical trial, 16 of 29 patients acquired mutations in members of the BCL-2 family of proteins, 14 of which were a mutation in BCL-2. In nine (9) of those 14 patients, the BCL-2 mutation was detected after 24 months on venetoclax. In an in vitro preclinical study, we assessed the affinity of ZN-d5 alongside venetoclax, to bind to such BCL-2 mutations, as measured in nM. In each assay, ZN-d5 was observed to bind with higher affinity to such BCL-2 mutants as compared to venetoclax.
 
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IC50 (nM)
BCL-2 Type
COMPOUNDWTG101VF104LD103Y
Venetoclax(1)
1.3 7.3 8.4 18.3 
ZN-d51.4 3.7 1.4 5.0 
(1)Data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company commercializing the compound.
Anti-Tumor Activity of ZN-d5 in Xenograft Leukemia Model
In a preclinical study, we assessed the anti-tumor activity of ZN-d5, alongside venetoclax. In a RS4;11 xenograft leukemia mouse model, ZN-d5, dosed at 50 mg/kg daily for a period of 11 days, showed potent anti-tumor activity with tumors shrinking upon treatment and yielding durable complete responses after cessation of dosing to the end of the study, as shown in the graphic below. We observed similar results with venetoclax in this model.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g22.gif
Toxicology
The IND enabling toxicology studies are currently ongoing.
ZN-e4, an Inhibitor of EGFR for the Treatment of NSCLC
Overview
We are developing ZN-e4, an irreversible inhibitor of EGFR, a regulator of a number of cellular functions, including proliferation and survival, and a driver of tumorigenesis in certain cancers, including lung cancer. We have designed ZN-e4 to be highly selective against mutant EGFR, and in animal studies, the metabolites of ZN-e4 do not include any compounds known to bind potently to the wild-type EGFR. We believe the presence of such, the production of which is believed to be responsible for the development of a number of toxicities, including skin rash. We believe that eliminating the formation of such a metabolite will allow for a wide therapeutic window. In addition, we believe a more tolerable EGFR inhibitor would, if approved, allow for use in combination while limiting the toxicity associated with use in combination.
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We are conducting a Phase 1/2 clinical trial of ZN-e4 in patients with advanced NSCLC with activating EGFR mutations, which we refer to as our ZN-e4-001 Trial. We are actively evaluating potential combination therapies for future clinical development of ZN-e4. We will evaluate whether to initiate the Phase 2 portion of this trial upon the completion of the Phase 1 portion and after considering trial design, patient population and combination strategies. We expect to report topline results from the Phase 1 portion of the trial in 2021.
 
Role of EGFR Inhibition in NSCLC
Lung cancer is the leading cause of cancer death for both men and women, accounting for approximately 18% of all cancer deaths globally. There are an estimated 228,000 new cases of lung cancer diagnosed and 143,000 deaths in the United States annually. More than half of the people with lung cancer die within one year of being diagnosed. Non-small cell lung cancer, or NSCLC, accounts for approximately 80-85% of lung cancer cases. EGFR mutations are detected in approximately 10% to 15% and 30% to 40% of Caucasian and Asian patients, respectively, with NSCLC.
EGFR mutations lead to activation of EGFR signaling and oncogenic transformation both in vitro and in vivo. Cancers with EGFR mutations depend on EGFR signaling for growth and survival and are often sensitive to treatment with EGFR inhibitors. Two (2) inhibitors of EGFR were approved in the early 2000s to treat patients with advanced NSCLC based on antitumor responses in a subset of patients. These first-generation drugs, erlotinib and gefitinib, were reversible EGFR inhibitors. Although most NSCLC patients with EGFR mutations displayed an initial pronounced response to these first-generation EGFR inhibitors, they acquired resistance to the drugs after approximately nine (9) to 14 months of treatment. The T790M mutation of EGFR was the most common mechanism of such an acquired resistance, having been detected in over 50% of patients treated with EGFR inhibitors.
A second-generation of EGFR inhibitors was developed to address this treatment resistance and to improve upon the efficacy of the first-generation therapies. The second-generation of EGFR inhibitors, including afatinib, marketed as Gilotrif® by Boehringer Ingelheim, and dacomitib, marketed as Vizimpro® by Pfizer, are irreversible inhibitors which covalently bind to EGFR. As such, they are more potent, but are associated with increased toxicity. Further, T790M-mediated acquired resistance occurred at a similar frequency in patients receiving a second-generation therapy as those receiving first generation therapy. Third-generation therapies, such as osimertinib, specifically targeting the T790M mutation have been clinically shown to be a useful strategy in the treatment of NSCLC.
FDA-Approved Third-Generation EGFR Inhibitor, Osimertinib
Osimertinib, which represents the third-generation of EGFR inhibitors, targets EGFR mutations and acquired resistance EGFR mutations such as T790M in order to improve upon the efficacy of previous generations of EGFR inhibitors. In a randomized Phase 3 clinical trial in patients with EGFR-mutated metastatic NSCLC, osimertinib demonstrated a median PFS period of 18.9 months versus 10.2 months for the control arm in which patients received gefitinib or erlotinib. Based on these results, osimertinib was approved by the FDA in November 2015. AstraZeneca reported sales of Tagrisso® of $4.3 billion in 2020, an increase of 36% from 2019 and are expected to grow to $9.5 billion in 2026.
Osimertinib was also designed to have reduced potency against non-mutated, or wild-type, EGFR found in healthy cells, thereby minimizing the toxicities associated with first and second-generation EGFR inhibitors. Despite its observed success in addressing the T790M-mediated acquired resistance and improved efficacy, osimertinib has a similar adverse event profile to first and second-generation EGFR inhibitors. As demonstrated by third-party clinical data, approximately 60% of patients dosed with osimertinib reported rashes compared to 80% of those dosed with gefitinib or erlotinib and a range of 70% to 90% for the second-generation EGFR inhibitor, afatinib. In addition, similar levels of gastrointestinal disorders such as diarrhea were observed in each of the patient populations. Osimertinib also has warnings and precautions regarding interstitial lung disease, QT prolongation, a surrogate marker for the risk of developing tachycardias, cardiomyopathy, keratitis and Stevens-Johnson Syndrome.
We believe one of the major metabolites of osimertinib, AZ5104, which accounts for approximately 9% to 10% of the total drug concentration at clinical doses, may be contributing to these toxicities. In addition, the off-target toxicities are exacerbated by the long half-life of osimertinib.
 
Our EGFR Solution: ZN-e4
ZN-e4 is our irreversible EGFR inhibitor product candidate which we have designed to potently inhibit mutant EGFR, including the T790M resistance mutation. We have designed ZN-e4 to be highly selective against mutant EGFR and have observed in preclinical studies that the administration of ZN-e4 does not produce a metabolite potent for wild-type EGFR. We
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have also designed ZN-e4 with improved physical-chemical characteristics, including improved solubility. In a head-to-head preclinical study, ZN-e4 showed greater than 450-fold solubility within 48 hours when compared to osimertinib.
We are evaluating ZN-e4 in our Phase 1/2 clinical trial in patients with advanced NSCLC. We believe ZN-e4, if approved, has the potential to be used as monotherapy and in combination with a number of therapies, including ZN-c3, our WEE1 inhibitor product candidate, if approved, tyrosine-protein kinase Met, or c-Met, inhibitors, mitogen-activated protein kinase, or MEK, inhibitors, and c-ros oncogene1 receptor tyrosine kinase, or ROS1, inhibitors. Results of various third-party preclinical studies and clinical trials support such combinations across a number of oncology indications and we continue to actively evaluate the potential of combinations for future clinical development with ZN-e4.
Preclinical Results
Selectivity Across EGFR Cell Lines
In a preclinical study, we evaluated the potency of ZN-e4 alongside osimertinib against three types of EGFR cell lines –double mutant (DM cell), single mutant (AM cell) and wild-type (WT cell). As shown in the table below, we observed similar potency in the DM and AM cell lines and three times greater selectivity than osimertinib based on the wild-type binding. In addition, we also observed that the administration of ZN-e4 did not produce a metabolite potent for wild type EGFR.
 
DOUBLE MUTANT CELL
IC50 (nM)
SINGLE MUTANT CELL
IC50 (nM)
WILD-TYPE CELL
IC50 (nM)
Osimertinib(1): Core Drug
15 29 294 
ZN-e4: Core Drug20 38 839 
(1)Osimertinib data based on evaluation of comparable proxy chemical compound purchased from commercial sources rather than the pharmaceutical company commercializing the compound.
Anti-tumor Activity, Tolerability and Solubility of ZN-e4
In a preclinical study, we evaluated the anti-tumor activity of ZN-e4 alongside that of osimertinib. In a NCI-H1975 NSCLC tumor model in which there is a double mutation in EGFR, T790M and L858R, oral dosing of ZN-e4 for 14 days at the dose tested, 10 mg/kg, induced complete tumor regression, as did 10 mg/kg osimertinib dosed orally. In addition, ZN-e4 at this dose was well tolerated in these models with no apparent loss in body weight throughout the study. In contrast, the 10 mg/kg dose of osimertinib led to a loss of greater than 8% of total body weight. We observed a similar loss of body weight with ZN-e4 when we increased the dose to 50 mg/kg, roughly five (5) times the dose we found to reduce tumor volumes.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g23.gif
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We also assessed the relative solubility of ZN-c3, alongside a proxy chemical compound of osimertinib, using a standard in vitro assay. The solubility of ZN-e4 was observed to be 1,614,000 nM, greater than 450 fold the solubility that of osimertinib which was observed at 3,500 nM. In addition, we did not observe confirmed cardiac toxicity as measured by the standard electrophysiological hERG safety assay.
Phase 1/2 Clinical Trial of ZN-e4
In April 2018, we initiated dosing in a Phase 1/2 open label, multi-center trial of ZN-e4 in patients with advanced NSCLC with activating EGFR mutations who have progressed following therapy with an EGFR tyrosine kinase inhibitor, which we refer to as our ZN-e4-001 Trial, to assess the safety, tolerability, PK and anti-tumor activity of ZN-e4. The study is currently being conducted across multiple sites in the United States, it consists of a Phase 1, monotherapy 3+3 dose escalation portion of this trial and a Phase 2 portion of this trial.
The primary objective of the Phase 1 portion of this trial is to determine the MTD of ZN-e4 as an oral monotherapy. The secondary objectives include assessing the safety and tolerability, determining a RP2D and characterizing the PK, of ZN-e4.
As of February 5, 2020, 19 patients had been enrolled in this trial in seven (7) dose level cohorts. We expect to report topline results from the Phase 1 portion of this trial in 2021. We will evaluate whether to initiate the Phase 2 portion of this trial upon the completion of the Phase 1 portion and after considering trial design, patient population and combination strategies.
Interim and Preliminary Clinical Results
As of the February 5, 2020 database cutoff date, we completed dosing in six (6) of our dose escalation cohorts and have enrolled two (2) patients in cohort seven. Nineteen patients have been enrolled and treated with doses of ZN-e4 ranging from 20 mg to 480 mg, once daily. At baseline, the mean age of the enrolled population was 63.9 years (range 38 to 86 years) and consisted of 47% females and 53% males. Of the enrolled patients, six (6) (31.6%) are continuing treatment and 13 (68.4%) have discontinued treatment, nine (9) of which were due to disease progression.
Enrolled patients have received the following prior lines of cancer treatment: EGFR tyrosine kinase inhibitors (16 of 19 patients), chemotherapy (12 of 19 patients), osimertinib (11 of 19 patients), immunotherapy (five (5) of 19 patients), investigational EGFR tyrosine kinase inhibitors (two (2) of 19 patients) and EGFR monoclonal antibodies (two (2) of 19 patients). Of the enrolled patients, 12 of the 19 had one to three prior systemic cancer regimens, and seven (7) of the 19 had four (4) or more.
The interim and preliminary data described herein are subject to change as more data on these patients and additional patients become available and are subject to authorization and verification procedures that could result in material changes in the final data.
Interim ZN-e4 Preliminary Safety Results
As of the February 5, 2020 database cutoff date, ZN-e4 was generally well tolerated. One patient reported a dose-limiting toxicity at the 320 mg dose level. The trial is currently ongoing at a dose level of 480 mg.
TEAEs occurred in 18 of 19 patients. No serious adverse events were reported. Two (2) deaths occurred during the safety reporting time period of the study, each due to progression of disease and determined to not be related to treatment.
The most frequent of these TEAEs observed were diarrhea (11 of 19 patients), nausea (six (6) of 19 patients), fatigue (six (6) of 19 patients), back pain (five (5) of 19 patients), cough (five (5) of 19 patients), dyspnea (four (4) of 19 patients) and vomiting (four (4) of 19 patients). All cases of diarrhea were Grade 1 except for one which was Grade 2. Rash of Grade 1 severity was only reported in one patient.
Investigator-assessed, treatment-related adverse events occurred in 11 of 19 patients. Of these treatment-related adverse events, nine (9) of 19 patients reported treatment-related adverse events of Grade 1 or Grade 2 severity and two (2) of 19 patients reported treatment-related adverse events of Grade 3 in severity; one case of dysphagia and two (2) cases of fatigue.
As of the February 5, 2020 database cutoff date, there was no apparent increase of incidence or severity of adverse events with increased dose.
 
Interim and Preliminary Efficacy Results
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As of the February 5, 2020 database cutoff date, we observed that two (2) patients, each of which was osimertinib naïve and one of which had the T790M mutation, had confirmed PR by RECIST criteria as showing their best overall response, one dosed at 160 mg and one at 320 mg. One patient dosed at 480 mg showed an unconfirmed PR as of the cutoff date. One other patient currently with stable disease had a reduction in target lesion size of approximately 29%.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g24.gif

Notes:
Includes data for the 16 evaluable patients as of the February 5, 2020 database cutoff date.
(zz mg : rr) indicates: (dose : best response, + if ongoing)
As of the database cutoff date, one patient had a treatment duration of 15.2 months and another patient had a treatment duration of 10.3 months.
 

The following table illustrates response, duration of remission and re-dosing of ZN-e4 in this trial as of the database cutoff date.
https://cdn.kscope.io/c882b9fe4fdc74faf6eae90c304e8e7e-zntl-20201231_g25.gif
Drug Pharmacokinetics
As of the February 5, 2020 database cutoff date, PK results were available for the first 17 patients dosed in our ZN-e4 Trial. The PK results from such patients showed rapid absorption into the systemic circulation, with typical median Tmax values
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of two (2) to four (4) hours. The exposures were observed to be dose dependent. Little to no ZN-e4 accumulation at steady state on day 15 of once daily dosing was observed with mean day 15 to day one AUC ratios of 1.0-1.8.

Dose (mg)DAY 15 (STEADY STATE)
Cmax
(ng/mL)
Tmax
(hr)
AUC0-8hr (ng*h/mL)
20Mean55.98376
(n=1)
40Mean36.98179
(n=1)
80Mean1444945
(n=1)SD65.3(2-4)487
160Mean38242,440
(n=3)SD274(2-4)1,630
240Mean53243,730
(n=3)SD117(4-6)926
320Mean38842,550
(n=5)SD203(2-4)1,410
Notes:
Median (range) are listed for Tmax

Manufacturing
We currently do not own or operate any manufacturing facilities. We rely, and expect to continue to rely for the foreseeable future, on third-party contract manufacturing organizations, or CMOs, to produce our product candidates for preclinical and clinical testing, as well as for commercial manufacture if our product candidates receive marketing approval. We require that our CMOs produce bulk drug substances and finished drug products in accordance with current Good Manufacturing Practices, or cGMPs, and all other applicable laws and regulations. We maintain agreements with our manufacturers that include confidentiality and intellectual property provisions to protect our proprietary rights related to our product candidates.
We have engaged CMOs to manufacture and package ZN-c5, ZN-c3, ZN-d5 and ZN-e4 for preclinical and clinical use. Additional CMOs are used to label and distribute ZN-c5, ZN-c3 and ZN-e4 for clinical use. We obtain our supplies from these CMOs on a purchase order basis and do not have long-term supply arrangements in place. Although we do not currently have contractual arrangements in place for redundant supply for all of these product candidates, it is our goal to identify and contract with at least two (2) manufacturers for active pharmaceutical ingredient and two (2) manufacturers for drug product. More broadly, for each of our product candidates, we intend to identify and qualify additional manufacturers to provide the active pharmaceutical ingredient and fill-and-finish services prior to seeking regulatory approval.
Competition
The biotechnology and pharmaceutical industries are characterized by rapid technological advancement, significant competition and an emphasis on intellectual property. We face potential competition from many different sources, including major and specialty pharmaceutical and biotechnology companies, academic research institutions, governmental agencies and public and private research institutions. Any product candidates that we successfully develop and commercialize will compete with current therapies and new therapies that may become available in the future.
Many of the companies against which we may compete have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals and marketing approved products than we do. Mergers and acquisitions in the pharmaceutical, biotechnology and diagnostic industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, our programs.
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Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize medicines that are safer, more effective, have fewer or less severe side effects, are more convenient or less expensive than any medicines we may develop. Our competitors also may obtain FDA or other regulatory approval for their product candidates more rapidly than we may obtain approval for ours, which could result in competitors establishing a strong market position before we are able to enter the market. We believe that the key competitive factors affecting the success of any of our product candidates, if approved, will include efficacy, combinability, safety profile, convenience, cost, level of promotional activity devoted to them and intellectual property protection.
If the product candidates for our priority programs are approved for the indications we are currently targeting, they will compete with the drugs discussed below. Furthermore, it is possible that other companies are also engaged in discovery or preclinical development of drug candidates for the same indications. These competitors, if successful in clinical development, may achieve regulatory approval and market adoption in advance of our product candidates, constraining our ability to gain significant market share for such product candidates. In addition, our product candidates, if approved, will complete with multiple approved drugs or drugs that may be approved for future indications for which we develop such product candidate.
 

Intellectual Property
We strive to protect the proprietary technology, inventions and improvements that are commercially important to our business, including seeking, maintaining, and defending patent rights, whether developed internally or licensed from third parties. We also rely on know-how relating to our proprietary technology and product candidates and continuing innovation to develop, strengthen and maintain our proprietary position. We also plan to rely on data exclusivity, market exclusivity and patent term extensions when available. Our commercial success will depend in part on our ability to obtain and maintain patent and other proprietary protection for our technology, inventions and improvements; to defend and enforce our proprietary rights, including any patents that we may own in the future; and to operate without infringing the valid and enforceable patents and other proprietary rights of third parties. Intellectual property rights may not address all potential threats to our competitive advantage.
With respect to our product candidates and processes we intend to develop and commercialize in the normal course of business, we intend, or understand that our licensors intend, to pursue patent protection covering, when possible, compositions, methods of use, dosing and formulations. We or our licensors also may pursue patent protection with respect to manufacturing and drug development processes and technologies. Obtaining and maintaining patent protection depends on compliance with various procedural, document submission, fee payment, and other requirements imposed by governmental patent agencies. We or our licensors may not be able to obtain patent protections for our compositions, methods of use, dosing and formulations, manufacturing and drug development processes and technologies throughout the world. Issued patents can provide protection for varying periods of time, depending upon the date of filing of the patent application, the date of patent issuance and the legal term of patents in the countries in which they are obtained. In general, patents issued for applications filed in the United States can provide exclusionary rights for 20 years from the earliest effective filing date. In addition, in certain instances, the term of an issued U.S. patent that is directed to or claims an FDA-approved product can be extended to recapture a portion of the term effectively lost as a result of the FDA regulatory review period, which is called “patent term extension.” The restoration period cannot be longer than five years and the total patent term, including the restoration period, must not exceed 14 years following FDA approval. The term of patents outside of the United States varies in accordance with the laws of the foreign jurisdiction, but typically is also 20 years from the earliest effective filing date. However, the actual protection afforded by a patent varies on a product-by-product basis, from country-to-country, and depends upon many factors, including the type of patent, the scope of its coverage, the availability of regulatory-related extensions, the availability of legal remedies in a particular country, and the validity and enforceability of the patent. Patent term may be inadequate to protect our competitive position on our products for an adequate amount of time.
The patent positions of companies like ours are generally uncertain and involve complex legal and factual questions. No consistent policy regarding the scope of claims allowable in patents in the field of biopharmaceuticals has emerged in the United States. The relevant patent laws and their interpretation outside of the United States is also uncertain. Changes in either the patent laws or their interpretation in the United States and other countries may diminish our ability to protect our technology or product candidates and could affect the value of such intellectual property. In particular, our ability to stop third parties from making, using, selling, offering to sell or importing products that infringe our intellectual property will depend in part on our success in obtaining and enforcing patent claims that cover our technology, inventions and improvements. We cannot guarantee that patents will be granted with respect to any of our pending patent applications or with respect to any patent applications we may file in the future, nor can we be sure that any patents that may be granted to us in the future will be commercially useful in protecting our products, the methods of use or manufacture of those products. Moreover, even our issued patents do not guarantee us the right to practice our technology in relation to the commercialization of our products. Patent and other
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intellectual property rights in the pharmaceutical and biotechnology space are evolving and involve many risks and uncertainties. For example, third parties may have blocking patents that could be used to prevent us from commercializing our product candidates and practicing our proprietary technology, and our issued patents may be challenged, invalidated, deemed unenforceable or circumvented, which could limit our ability to stop competitors from marketing-related products or could limit the term of patent protection that otherwise may exist for our product candidates. In addition, the scope of the rights granted under any issued patents may not provide us with protection or competitive advantages against competitors with similar technology. Furthermore, our competitors may independently develop similar technologies that are outside the scope of the rights granted under any issued patents. For these reasons, we may face competition with respect to our product candidates. Moreover, because of the extensive time required for development, testing and regulatory review of a potential product, it is possible that, before any particular product candidate can be commercialized, any patent directed to such product may expire or remain in force for only a short period following commercialization, thereby reducing the commercial advantage the patent provides.
In-licensed Patents and Patent Applications
Recurium IP Holdings, LLC or Zeno Management, Inc., are currently the listed owner/assignee, or retained the exclusive license to 51 families of patent applications directed to our technology across our pipeline. As of March 22, 2021, our in-licensed portfolio consists of fourteen U.S. patents and eighteen foreign patents in nine (9) jurisdictions, including Europe, Australia, New Zealand, China, Hong Kong, India, Japan, Singapore and Taiwan.
As of March 22, 2021, 15 of the 51 families have a single application pending, and 36 of 51 families have multiple applications pending. The 51 families include 45 U.S. applications (including pending U.S. provisional patent applications and pending U.S. non-provisional patent applications), 43 PCT applications and more than 200 international applications in approximately 18 countries, including major markets in North America, South America, Europe and Asia, each having a nominal expiration date ranging from 2034 to 2041. The nominal expiration of our patents and patent applications does not account for any applicable patent term adjustments or extensions.
U.S. Patent No. 10,513,509, or the ‘509 Patent, includes claims directed to composition of matter, including ZN-e4, a pharmaceutical composition, a method for inhibiting replication of a malignant growth or a tumor, a method for ameliorating or treating a cancer and a method for inhibiting the activity of EGFR. The ‘509 Patent has an expected expiration date in May 2037. However, we believe the ‘509 Patent may be eligible for a patent term extension under the Hatch-Waxman Act.
One of the aforementioned pending U.S. and PCT patent applications includes claims directed to ZN-c5, ZN-c3 or ZN-d5, and has an expected expiration in 2037 (ZN-c5) and 2039 (ZN-c3 and ZN-d5). However, there can be no assurance that any of our pending in-licensed patent applications will issue. Furthermore, there can be no assurance that we will benefit from any patent term extension or favorable adjustments to the term of any of our in-licensed issued patents or patents that are issued in the future. The applicable authorities, including the FDA in the United States, may not agree with our assessment of whether such patent term extensions should be granted, and, if granted, they may grant more limited extensions than we request.
Trademarks
As of July 8, 2020, our trademark portfolio contains the following trademarks applications or registrations. U.S. trademark applications are pending for each of the marks ZENTALIS and the stylized “Z” mark. The mark ZENO has a registered U.S. trademark. Applications to register the marks ZENO and ZENTALIS have been filed internationally. The portfolio has an International Madrid Trademark Application designating Australia, Europe, Israel, Japan, Mexico, New Zealand, the Russian Federation, the United Kingdom and Singapore for the mark ZENO. The portfolio also has pending applications for registration and/or a registration has issued for one or more classes in Argentina, Brazil, Canada, Hong Kong and Taiwan for the mark ZENO. The portfolio also has an International Madrid Trademark Application designating Australia, Brazil, Canada, China, Europe, the United Kingdom, Israel, India, Japan, Korea, Mexico, New Zealand, the Russian Federation and Singapore for the mark ZENTALIS. The portfolio also has pending applications for registration in Argentina, Hong Kong, and Taiwan for the mark ZENTALIS.

Furthermore, we rely upon know-how, continuing technological innovation and potential in-licensing opportunities to develop and maintain our competitive position. We seek to protect our proprietary information, in part, using confidentiality and invention assignment agreements with our commercial partners, collaborators, employees, and consultants. These agreements are designed to protect our proprietary information and, in the case of the invention assignment agreements, to grant us ownership of technologies that are developed through a relationship with an employee or a third party. These agreements may be breached, and we may not have adequate remedies for any such breach. To the extent that our commercial partners,
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collaborators, employees and consultants use intellectual property owned by others in their work for us, disputes may arise as to the rights in related or resulting know-how and inventions.
Licensing Agreements and Strategic Collaborations
Recurium IP Holdings, LLC
In December 2014, and as amended and restated effective as of December 2017 and September 2019 and as amended in May 2020, we entered into a license agreement, or the Recurium Agreement, with Recurium IP Holdings, LLC, or Recurium IP under which we were granted an exclusive worldwide license to certain intellectual property rights owned or controlled by Recurium IP to develop and commercialize pharmaceutical products for the treatment or prevention of disease, other than for pain. In connection with the May 2020 amendment, we clarified certain aspects of the sublicensing payment provisions. We have the right to sublicense our rights under the Recurium Agreement, subject to certain conditions. We are required to use commercially reasonable efforts to develop and commercialize at least one product that comprises or contains a licensed compound and to execute certain development activities.
Under the terms of the Recurium Agreement, we are obligated to make development and regulatory milestone payments, pay royalties for net sales and make sublicensing payments with respect to certain licensed products directed to one of ten specific biological targets, including ZN-c5, ZN-c3 and ZN-e4. We are obligated to make development and regulatory milestone payments for such licensed products of up to $44.5 million. In addition, we are obligated to make milestone payments up to $150,000 for certain licensed products used in animals. We are also obligated to pay royalties on sales of such licensed products at a mid- to high-single digit percentage. In addition, if we choose to sublicense or assign to any third parties our rights under the Recurium Agreement with respect to such licensed products, we must pay to Recurium IP 20% of sublicensing income received in connection with such transaction.
Our royalty obligations will expire on a licensed product-by-licensed product and country-by-country basis on the later of fifteen years from the date of first commercial sale or when there is no longer a valid patent claim covering such licensed product in such country. The Recurium Agreement will expire on the later of on a country-by-country basis the expiration of royalty term for all licensed products in such country and December 21, 2032. The Recurium Agreement may be terminated in its entirety either by Recurium or by us in the event of an uncured material breach by the other party, in the event the other party is subject to specified bankruptcy, insolvency or similar circumstances, or in the event of a force majeure event under certain circumstances.
Upon termination of the Recurium Agreement for any reason, all rights and licenses granted to us under the agreement will terminate and revert to Recurium, and in the event of certain termination events, we would grant Recurium worldwide, royalty-bearing rights to our licensed products and transfer to Recurium any regulatory filings and data for such licensed products.
Mayo Foundation for Medical Education and Research
In February 2016, and as amended in April 2017 and December 2017, we entered into an option agreement, or the Mayo Agreement, with Mayo Foundation for Medical Education and Research under which we were granted an exclusive option to obtain a nonexclusive worldwide license to know-how and an exclusive worldwide license to related patent rights created by Mayo under the Mayo Agreement. The Mayo Agreement provided that it will expire on the date of the last to expire of the Mayo patent rights or, if no Mayo patent rights arise, on February 11, 2021. No Mayo patent rights were created under the Mayo Agreement and therefore the agreement expired on February 11, 2021. In consideration for the grant of know-how we provided grants of common stock on the first anniversary and Class A common units on the second and third anniversaries following entry into the Mayo Agreement. As of December 31, 2020, we have granted equity securities which amount to 15,435 shares of common stock under the Mayo Agreement.
SciClone Pharmaceuticals International (Cayman) Development Ltd.
In December 2014, and as amended in December 2016, we entered into a collaboration and license agreement, or the SciClone Agreement, with SciClone Pharmaceuticals International (Cayman) Development Ltd., or SciClone, under which we granted an exclusive license to certain intellectual property rights in the People’s Republic of China (including the territories of Macao and Hong Kong), South Korea, Taiwan and Vietnam, or the SciClone Territory, for SciClone to develop and commercialize a licensed product for the treatment or prevention of oncologic diseases and an exclusive option to obtain a similar license for up to two (2) additional licensed products. Under the SciClone Agreement, SciClone is responsible for clinical development activities required in order to obtain regulatory approval in the SciClone Territory. SciClone paid to us a
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one-time up-front payment of $1.0 million upon entering into the SciClone Agreement, and $4.0 million in aggregate milestone payments. No additional development or commercial milestones or reimbursement for research and development expenses are payable under the SciClone Agreement, as amended. We are entitled to receive a mid-single digit royalty on net sales of licensed products in the SciClone Territory, which royalty is subject to certain reductions in the event that SciClone is unable to achieve certain gross margins or if generic products are sold or if technology covering a licensed product is licensed from a third party. We have also agreed to pay SciClone tiered royalties pursuant to the terms of the SciClone Agreement, the applicable rate of which are determined based on whether a compound is developed to a successful dual IND submission and the costs incurred by SciClone for the development of such product candidate. SciClone’s and our royalty obligations will expire on a licensed product-by-licensed product and country-by-country basis on the later of fifteen years from the date of first commercial sale or when there is no longer a valid patent claim covering such licensed product in such country.
 
Following the December 2016 amendment to the SciClone Agreement, SciClone retains the exclusive license to develop our EGFR inhibitor product candidate, ZN-e4, in the SciClone Territory and the exclusive option to obtain an exclusive license to up to two (2) specified compounds under the SciClone Agreement for which we submit an IND by providing notice and paying $5 million to us. The SciClone Agreement will expire at the later of on a country-by-country basis the expiration of royalty term for all licensed products in such country and 15 years after the effective date of such agreement. The SciClone Agreement may be terminated in its entirety or on a country-by-country basis by SciClone upon 180 days’ notice or either by SciClone or by us in its entirety in the event of an uncured material breach by the other party, in the event the other party is subject to specified bankruptcy, insolvency or similar circumstances, or in the event of a force majeure event under certain circumstances.
Pfizer Clinical Trial Collaboration and Supply Agreement
In May 2018, we entered into a clinical trial collaboration and supply agreement with Pfizer, Inc. to evaluate the safety, tolerability and efficacy of ZN-c5 in combination with their CDK4/6 inhibitor, palbociclib, in our ongoing Phase 1/2 clinical trial of ZN-c5. Pursuant to this agreement, we will be responsible for the conduct and cost of the relevant studies, under the supervision of a joint development committee made up of our representatives and representatives of Pfizer that meets quarterly. Pfizer will supply palbociclib for use in the ZN-c5-001 Trial, at no cost to us. We are required to provide to Pfizer clinical data and other reports upon completion of the ZN-c5-001 Trial.
This agreement does not grant any right of first negotiation to participate in future clinical trials, and each of the parties retains all rights and ability to evaluate their respective compounds in any clinical studies, either as monotherapy or in combination with any other product or compound, in any therapeutic area.
The agreement with Pfizer will expire upon completion of all obligations of the parties thereunder or upon termination by either party. We and Pfizer each have the right to terminate the agreement for material breach by the other party. In addition, the agreement may be terminated by either party due to safety considerations or if either party decides to discontinue development of its own compound for medical, scientific, legal or other reasons or if a regulatory authority takes any action preventing that party from supplying its compound for the study. Pfizer also has the right to terminate this agreement if it notifies us in writing that it reasonably and in good faith believes that palbociclib is being used in an unsafe manner, and we fail to incorporate changes to address such issue, and the joint development committee is unable to resolve the issue following elevation to appropriate parties.
Eli Lilly and Company Clinical Trial Collaboration and Supply Agreement
In July 2020, we entered into a clinical trial collaboration and supply agreement with Eli Lilly and Company, or Lilly, to evaluate ZN-c5 in combination with their CDK 4/6 inhibitor, abemaciclib, in a planned Phase 1b open label multi-center clinical trial that we intend to initiate in the second half of 2020. Pursuant to this agreement, we will be responsible for the conduct and cost of the relevant studies. We and Lilly will each designate a project manager that will meet no less than twice yearly and will be responsible for implementing and coordinating activities, and facilitating the exchange of information, with respect to the study. Lilly is obligated to supply abemaciclib for use in the trial, at no cost to us. We are required to provide to Lilly clinical data and other reports at major decision points during the trial and no later than 60 days following completion of the planned Phase 1b clinical trial.
This agreement does not grant any right of first negotiation to participate in future clinical trials, and each of the parties retains all rights and ability to evaluate their respective compounds in any clinical studies, either as monotherapy or in combination with any other product or compound, in any therapeutic area.
 
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The agreement with Lilly will expire upon completion of all obligations of the parties thereunder or upon termination by either party. We and Lilly each have the right to terminate the agreement for material breach by the other party. In addition, the agreement may be terminated by either party due to safety considerations or if either party decides to discontinue development of its own compound for medical, scientific, legal or other reasons or if a regulatory authority takes any action preventing that party from supplying its compound for the study. Lilly also has the right to terminate this agreement if it notifies us in writing that it reasonably and in good faith believes that abemaciclib is being used in an unsafe manner, and we fail to incorporate changes to address such issue, and the issue is unable to be resolved following elevation to appropriate parties.

Zentera Therapeutics
In May 2020, each of our subsidiaries Zeno Alpha, Inc., K-Group Alpha, Inc. and K-Group Beta, Inc. entered into a collaboration and license agreement with our majority-owned joint venture, Zentera Therapeutics (Cayman), Ltd., or Zentera (the “Zentera Sublicenses”), pursuant to which we collaborate with Zentera on the development and commercialization of ZN-c5, ZN-d5 and ZN-c3, respectively, whether alone or in a licensed product (“Collaboration Products”) in each case for the treatment or prevention of disease, other than for pain (the “Zentera Field”), in the People’s Republic of China, Macau, Hong Kong and Taiwan (the “Zentera Collaboration Territory”). Under each Zentera Sublicense, Zentera will lead development, and upon regulatory approval, the commercialization, of the Collaboration Products in the Zentera Collaboration Territory. On May 19, 2020, Zentera issued an aggregate of 60.2% of its issued shares of common stock to Zeno Alpha, Inc., K-Group Alpha, Inc., K-Group Beta, Inc., Zeno Management, Inc. and Zeno Beta, Inc. Anthony Y. Sun, M.D., our President and Chief Executive Officer, serves as Chief Executive Officer and a member of the board of directors of Zentera and Kevin D. Bunker, Ph.D, our Chief Operating Officer, serves as a member of the board of directors of Zentera.
Under each Zentera Sublicense, we granted Zentera an exclusive, royalty-bearing license under certain of our technology, including technology licensed from Recurium under the Recurium Agreement, to develop and commercialize the Collaboration Products in the Zentera Field and in the Zentera Collaboration Territory, subject to certain rights that we retain, and upon a successful manufacturing transfer, a non-exclusive license under certain of our manufacturing technology to manufacture Collaboration Products in the Zentera Field and in the Zentera Collaboration Territory. Zentera has the right to sublicense its rights under the Zentera Sublicenses subject to certain conditions.
Under the terms of the Zentera Sublicenses, Zentera is responsible for the costs of developing the Collaboration Products in the Zentera Collaboration Territory, and we are responsible for the costs of developing the Collaboration Products outside the Zentera Collaboration Territory, provided that Zentera will reimburse us for a portion of its costs for global data management, pharmacovigilance, safety database management, and chemistry, manufacturing and controls activities with respect to each Collaboration Product. Under the Zentera Sublicenses, we will be eligible to receive future development and regulatory milestones of up to $4.45 million per Collaboration Product. Zentera will pay us royalties on net sales of Collaboration Products in the Zentera Collaboration Territory at a mid- to high-single digit percentage subject to certain reductions. In addition, if Zentera or its affiliate chooses to sublicense or assign to any third parties its rights under the Zentera Sublicenses with respect to any Collaboration Product, Zentera must pay to us 20% of sublicensing income received by Zentera or its affiliates in connection with such transaction.
Zentera’s royalty obligations continue with respect to each region within the Collaboration Territory and each Collaboration Product until the later of (i) the date on which such Collaboration Product is no longer covered by a valid claim of a licensed patent, and (ii) the 15th anniversary of the first commercial sale of such Collaboration Product in such region. Each Zentera Sublicense will expire on a region-by-region basis at the expiration of the royalty term for the Collaboration Product in such region.
Each Zentera Sublicense may be terminated in its entirety either by Zentera or by us in the event of an uncured material breach by the other party, in the event the other party is subject to bankruptcy, insolvency or similar circumstances, or in the event of a force majeure event under certain circumstances. In addition, Zentera may terminate each Zentera Sublicense upon 180 days’ notice to us after the first regulatory approval of the licensed compound in the People’s Republic of China, or if the applicable licensed compound does not achieve regulatory approval in the People’s Republic of China within the timeframe set forth in the initial regional development plan or as otherwise agreed by the parties. We may terminate each Zentera Sublicense if Zentera fails to meet certain diligence obligations under such Zentera Sublicense.
Upon termination of each Zentera Sublicense for any reason, all rights and licenses granted to Zentera under the agreement will terminate and revert to us. In the event of termination, Zentera would assign to us certain intellectual property related to the applicable Collaboration Products and transfer to Zentera any regulatory filings and data for such Collaboration Products, and, in the event of termination by Zentera for convenience, due to a breach by us, or due to our insolvency, we
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would pay Zentera royalties at a mid-single digit percentage on net sales in the Zentera Collaboration Territory of any Collaboration Product for which clinical trial data was generated by Zentera until certain of Zentera’s development, manufacturing and certain commercialization costs accrued, if any, have been reimbursed.
Government Regulation and Product Approval
Government authorities in the United States, at the federal, state and local level, and other countries extensively regulate, among other things, the research, development, testing, manufacture, quality control, approval, labeling, packaging, storage, record-keeping, promotion, advertising, distribution, marketing and export and import of products such as those we are developing. A new drug must be approved by the FDA through the NDA process before it may be legally marketed in the United States.
U.S. Drug Development Process
In the United States, the FDA regulates drugs under the federal Food, Drug, and Cosmetic Act, or the FDCA, and its implementing regulations. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources.
The process required by the FDA before a drug may be marketed in the United States generally involves the following:
 
completion of preclinical laboratory tests, animal studies and formulation studies in accordance with FDA’s good laboratory practice requirements and other applicable regulations;
submission to the FDA of an IND, which must become effective before human clinical trials may begin;
approval by an independent IRB ethics committee at each clinical site before each trial may be initiated;
performance of adequate and well-controlled human clinical trials in accordance with GCP requirements to establish the safety and efficacy of the proposed drug for its intended use;
submission to the FDA of an NDA after completion of all pivotal trials;
satisfactory completion of an FDA advisory committee review, if applicable;
satisfactory completion of an FDA inspection of the manufacturing facility or facilities at which the drug is produced to assess compliance with cGMP requirements to assure that the facilities, methods and controls are adequate to preserve the drug’s identity, strength, quality and purity, and of selected clinical investigation sites to assess compliance with GCPs; and
FDA review and approval of the NDA to permit commercial marketing of the product for particular indications for use in the United States.
Prior to beginning the first clinical trial with a product candidate in the United States, a sponsor must submit an IND to the FDA. An IND is a request for authorization from the FDA to administer an investigational new drug product to humans. The central focus of an IND submission is on the general investigational plan and the protocol(s) for clinical studies. The IND also includes results of animal and in vitro studies assessing the toxicology, pharmacokinetics, pharmacology, and pharmacodynamic characteristics of the product; chemistry, manufacturing, and controls information; and any available human data or literature to support the use of the investigational product. An IND must become effective before human clinical trials may begin. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30- day time period, raises safety concerns or questions about the proposed clinical trial. In such a case, the IND may be placed on clinical hold and the IND sponsor and the FDA must resolve any outstanding concerns or questions before the clinical trial can begin. Submission of an IND therefore may or may not result in FDA authorization to begin a clinical trial.
Clinical trials involve the administration of the investigational product to human subjects under the supervision of qualified investigators in accordance with GCPs, which include the requirement that all research subjects provide their informed consent for their participation in any clinical study. Clinical trials are conducted under protocols detailing, among other things, the objectives of the study, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. A separate submission to the existing IND must be made for each successive clinical trial conducted during product development and for any subsequent protocol amendments. Furthermore, an independent IRB for each site proposing to conduct the clinical trial must review and approve the plan for any clinical trial and its informed consent form before the clinical trial begins at that site and must monitor the study until completed. Regulatory authorities, the IRB or the sponsor may suspend a clinical trial at any time on various grounds, including a finding that the subjects are being exposed to an unacceptable health risk or that the trial is unlikely to meet its stated objectives. Some studies also include oversight by an independent group of qualified experts organized by the clinical study sponsor, known as a data safety monitoring board, which provides authorization for whether or not a study may move forward at designated check points based on access to certain data from the study and may halt the clinical trial if it determines that there is an unacceptable safety risk for subjects or other grounds, such as no demonstration of
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efficacy. There are also requirements governing the reporting of ongoing clinical studies and clinical study results to public registries.
Human clinical trials are typically conducted in three sequential phases that may overlap or be combined:
 
Phase 1: The product candidate is initially introduced into healthy human subjects or patients with the target disease or condition. These studies are designed to test the safety, dosage tolerance, absorption,
metabolism and distribution of the investigational product in humans, the side effects associated with increasing doses, and, if possible, to gain early evidence on effectiveness. In the case of some products for severe or life-threatening diseases, such as cancer, especially when the product may be too inherently toxic to ethically administer to healthy volunteers, the initial human testing is often conducted in patients.
Phase 2: The product candidate is administered to a limited patient population with a specified disease or condition to evaluate the preliminary efficacy, optimal dosages and dosing schedule and to identify possible adverse side effects and safety risks. Multiple Phase 2 clinical trials may be conducted to obtain information prior to beginning larger and more expensive Phase 3 clinical trials.
Phase 3: The product candidate is administered to an expanded patient population to further evaluate dosage, to provide statistically significant evidence of clinical efficacy and to further test for safety, generally at multiple geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk/benefit ratio of the investigational product and to provide an adequate basis for product approval.
Post-approval trials, sometimes referred to as Phase 4 studies, may be conducted after initial marketing approval. These trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication. In certain instances, the FDA may mandate the performance of Phase 4 clinical trials as a condition of approval of an NDA.
Concurrent with clinical trials, companies usually complete additional animal studies and must also develop additional information about the chemistry and physical characteristics of the drug and finalize a process for manufacturing the product in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, the manufacturer must develop methods for testing the identity, strength, quality and purity of the final drug. In addition, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the product candidate does not undergo unacceptable deterioration over its shelf life.
During the development of a new drug, sponsors are given opportunities to meet with the FDA at certain points. These points may be prior to submission of an IND, at the end of Phase 2, and before an NDA is submitted. Meetings at other times may be requested. These meetings can provide an opportunity for the sponsor to share information about the data gathered to date, for the FDA to provide advice, and for the sponsor and the FDA to reach agreement on the next phase of development. Sponsors typically use the meetings at the end of the Phase 2 trial to discuss Phase 2 clinical results and present plans for the pivotal Phase 3 clinical trials that they believe will support approval of the new drug.
While the IND is active and before approval, progress reports summarizing the results of the clinical trials and nonclinical studies performed since the last progress report must be submitted at least annually to the FDA, and written IND safety reports must be submitted to the FDA and investigators for serious and unexpected suspected adverse events, findings from other studies suggesting a significant risk to humans exposed to the same or similar drugs, findings from animal or in vitro testing suggesting a significant risk to humans, and any clinically important increased incidence of a serious suspected adverse reaction compared to that listed in the protocol or investigator brochure.

U.S. Review and Approval Process
Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, the results of product development, preclinical and other non-clinical studies and clinical trials, along with descriptions of the manufacturing process, analytical tests conducted on the chemistry of the drug, proposed labeling and other relevant information are submitted to the FDA as part of an NDA requesting approval to market the product. The submission of an NDA is subject to the payment of substantial user fees; a waiver of such fees may be obtained under certain limited circumstances. Additionally, no user fees are assessed on NDAs for products designated as orphan drugs, unless the product also includes a non-orphan indication.
The FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use and whether its manufacturing is cGMP-compliant to assure and preserve the product’s identity, strength, quality and purity. Under the Prescription Drug User Fee Act, or PDUFA, guidelines that are currently in effect, the FDA has a goal of ten months
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from the date of “filing” of a standard NDA for a new molecular entity to review and act on the submission. This review typically takes twelve months from the date the NDA is submitted to FDA because the FDA has approximately two (2) months to make a “filing” decision after it the application is submitted. The FDA conducts a preliminary review of all NDAs within the first 60 days after submission, before accepting them for filing, to determine whether they are sufficiently complete to permit substantive review The FDA may request additional information rather than accept an NDA for filing. In this event, the NDA must be resubmitted with the additional information. The resubmitted application also is subject to review before the FDA accepts it for filing.
The FDA may refer an application for a novel drug to an advisory committee. An advisory committee is a panel of independent experts, including clinicians and other scientific experts, that reviews, evaluates and provides a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions.
Before approving an NDA, the FDA will typically inspect the facility or facilities where the product is manufactured. The FDA will not approve an application unless it determines that the manufacturing processes and facilities are in compliance with cGMP and adequate to assure consistent production of the product within required specifications. Additionally, before approving a NDA, the FDA will typically inspect one or more clinical sites to assure compliance with GCPs. If the FDA determines that the application, manufacturing process or manufacturing facilities are not acceptable, it will outline the deficiencies in the submission and often will request additional testing or information. Notwithstanding the submission of any requested additional information, the FDA ultimately may decide that the application does not satisfy the regulatory criteria for approval.
After the FDA evaluates an NDA, it will issue an approval letter or a Complete Response Letter. An approval letter authorizes commercial marketing of the drug with prescribing information for specific indications. A Complete Response Letter indicates that the review cycle of the application is complete, and the application will not be approved in its present form. A Complete Response Letter usually describes the specific deficiencies in the NDA identified by the FDA and may require additional clinical data, such as an additional pivotal Phase 3 trial or other significant and time-consuming requirements related to clinical trials, nonclinical studies or manufacturing. If a Complete Response Letter is issued, the sponsor must resubmit the NDA or, addressing all of the deficiencies identified in the letter, or withdraw the application. Even if such data and information are submitted, the FDA may decide that the NDA does not satisfy the criteria for approval.
If regulatory approval of a product is granted, such approval will be granted for particular indications and may entail limitations on the indicated uses for which such product may be marketed. For example, the FDA may approve the NDA with a REMS to ensure the benefits of the product outweigh its risks. A REMS is a safety strategy to manage a known or potential serious risk associated with a medicine and to enable patients to have continued access to such medicines by managing their safe use, and could include medication guides, physician communication plans, or elements to assure safe use, such as restricted distribution methods, patient registries, and other risk minimization tools. The FDA also may condition approval on, among other things, changes to proposed labeling or the development of adequate controls and specifications. Once approved, the FDA may withdraw the product approval if compliance with pre- and post-marketing requirements is not maintained or if problems occur after the product reaches the marketplace. The FDA may also require one or more Phase 4 post-market studies and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization, and may limit further marketing of the product based on the results of these post-marketing studies. In addition, new government requirements, including those resulting from new legislation, may be established, or the FDA’s policies may change, which could impact the timeline for regulatory approval or otherwise impact ongoing development programs.
In addition, the Pediatric Research Equity Act, or PREA, requires a sponsor to conduct pediatric clinical trials for most drugs, for a new active ingredient, new indication, new dosage form, new dosing regimen or new route of administration. Under PREA, original NDAs and supplements must contain a pediatric assessment unless the sponsor has received a deferral or waiver. The required assessment must evaluate the safety and effectiveness of the product for the claimed indications in all relevant pediatric subpopulations and support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The sponsor or FDA may request a deferral of pediatric clinical trials for some or all of the pediatric subpopulations. A deferral may be granted for several reasons, including a finding that the drug is ready for approval for use in adults before pediatric clinical trials are complete or that additional safety or effectiveness data needs to be collected before the pediatric clinical trials begin. The FDA must send a non-compliance letter to any sponsor that fails to submit the required assessment, keep a deferral current or fails to submit a request for approval of a pediatric formulation.
Expedited Development and Review Programs
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The FDA offers a number of expedited development and review programs for qualifying product candidates. For example, the FDA has a fast track designation program that is intended to expedite or facilitate the process for reviewing new drug products that meet certain criteria. Specifically, new drugs are eligible for fast track designation if they are intended to treat a serious or life-threatening disease or condition and demonstrate the potential to address unmet medical needs for the disease or condition. Fast track designation applies to the combination of the product and the specific indication for which it is being studied. The sponsor of a fast track product candidate has opportunities for more frequent interactions with the applicable FDA review team during product development. With regard to a fast track product, the FDA may consider for review sections of the NDA on a rolling basis before the complete application is submitted, if the sponsor provides a schedule for the submission of the sections of the NDA, the FDA agrees to accept sections of the NDA and determines that the schedule is acceptable, and the sponsor pays any required user fees upon submission of the first section of the NDA.
A product candidate intended to treat a serious or life-threatening disease or condition may also be eligible for Breakthrough Therapy designation to expedite its development and review. A product candidate can receive Breakthrough Therapy designation if preliminary clinical evidence indicates that the product candidate, alone or in combination with one or more other drugs or biologics, may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The designation includes all of the fast track program features, as well as more intensive FDA interaction and guidance beginning as early as Phase 1 and an organizational commitment to expedite the development and review of the product candidate, including involvement of senior managers.
Any product candidate submitted to the FDA for approval, including a product candidate with a fast track designation, may also be eligible for other types of FDA programs intended to expedite development and review, such as priority review and accelerated approval. A product candidate is eligible for priority review if it has the potential to provide a significant improvement in the treatment, diagnosis or prevention of a disease compared to marketed products. The FDA will attempt to direct additional resources to the evaluation of an application for a new drug designated for priority review in an effort to facilitate the review. The FDA endeavors to review applications with priority review designations within six (6) months of the filing date as compared to ten months for review of new molecular entity NDAs under its current PDUFA review goals.
In addition, a product candidate may be eligible for accelerated approval. Drug products intended to treat serious or life-threatening diseases or conditions may be eligible for accelerated approval upon a determination that the product has an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit, or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality, that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. As a condition of approval, the FDA may require that a sponsor of a drug receiving accelerated approval perform adequate and well-controlled post-marketing clinical trials to verify and describe the anticipated effect on irreversible morbidity or mortality or other clinical benefit. Products receiving accelerated approval may be subject to expedited withdrawal procedures if the sponsor fails to conduct the required post-marketing studies or if such studies fail to verify the predicted clinical benefit. In addition, the FDA currently requires pre-approval of promotional materials as a condition for accelerated approval, which could adversely impact the timing of the commercial launch of the product.
Fast track designation, breakthrough therapy designation, priority review, and accelerated approval do not change the standards for approval, but may expedite the development or approval process. Even if a product candidate qualifies for one or more of these programs, the FDA may later decide that the product candidate no longer meets the conditions for qualification or decide that the time period for FDA review or approval will not be shortened.
Post-approval Requirements
Any products manufactured or distributed by us pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA, including, among other things, requirements relating to record-keeping, reporting of adverse experiences, periodic reporting, product sampling and distribution, and advertising and promotion of the product. After approval, most changes to the approved product, such as adding new indications or other labeling claims, are subject to prior FDA review and approval. There also are continuing, annual program fees for any marketed products. Drug manufacturers and their subcontractors are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP, which impose certain procedural and documentation requirements upon us and our third-party manufacturers. Changes to the manufacturing process are strictly regulated, and, depending on the significance of the change, may require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMP and impose reporting requirements upon us and any third-party manufacturers that we may decide to use. Accordingly, manufacturers must continue
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to expend time, money and effort in the area of production and quality control to maintain compliance with cGMP and other aspects of regulatory compliance.
The FDA may withdraw approval if compliance with regulatory requirements and standards is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with manufacturing processes, or failure to comply with regulatory requirements, may result in revisions to the approved labeling to add new safety information; imposition of post-market studies or clinical studies to assess new safety risks; or imposition of distribution restrictions or other restrictions under a REMS program. Other potential consequences include, among other things:
 
restrictions on the marketing or manufacturing of the product, complete withdrawal of the product from the market or product recalls;
fines, warning letters, or untitled letters;
clinical holds on clinical studies;
refusal of the FDA to approve pending applications or supplements to approved applications, or suspension or revocation of product license approvals;
product seizure or detention, or refusal to permit the import or export of products;
consent decrees, corporate integrity agreements, debarment or exclusion from federal healthcare programs;
mandated modification of promotional materials and labeling and the issuance of corrective information;
the issuance of safety alerts, Dear Healthcare Provider letters, press releases and other communications containing warnings or other safety information about the product; or
injunctions or the imposition of civil or criminal penalties.
The FDA closely regulates the marketing, labeling, advertising and promotion of drug products. A company can make only those claims relating to safety and efficacy, purity and potency that are approved by the FDA and in accordance with the provisions of the approved label. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses. Failure to comply with these requirements can result in, among other things, adverse publicity, warning letters, corrective advertising and potential civil and criminal penalties. Physicians may prescribe, in their independent professional medical judgment, legally available products for uses that are not described in the product’s labeling and that differ from those tested by us and approved by the FDA. Physicians may believe that such off-label uses are the best treatment for many patients in varied circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however, restrict manufacturer’s communications on the subject of off-label use of their products. The federal government has levied large civil and criminal fines against companies for alleged improper promotion of off-label use and has enjoined companies from engaging in off-label promotion. The FDA and other regulatory agencies have also required that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed. However, companies may share truthful and not misleading information that is otherwise consistent with a product’s FDA-approved labelling.
Marketing Exclusivity
Market exclusivity provisions authorized under the FDCA can delay the submission or the approval of certain marketing applications. The FDCA provides a five-year period of non-patent marketing exclusivity within the United States to the first applicant to obtain approval of an NDA for a new chemical entity. A drug is a new chemical entity if the FDA has not previously approved any other new drug containing the same active moiety, which is the molecule or ion responsible for the action of the drug substance. During the exclusivity period, the FDA may not approve or even accept for review an abbreviated new drug application, or ANDA, or an NDA submitted under Section 505(b)(2), or 505(b)(2) NDA, submitted by another company for another drug based on the same active moiety, regardless of whether the drug is intended for the same indication as the original innovative drug or for another indication, where the applicant does not own or have a legal right of reference to all the data required for approval. However, an application may be submitted after four (4) years if it contains a certification of patent invalidity or non-infringement to one of the patents listed with the FDA by the innovator NDA holder.
The FDCA alternatively provides three years of marketing exclusivity for an NDA, or supplement to an existing NDA if new clinical investigations, other than bioavailability studies, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application, for example new indications, dosages or strengths of an existing drug. This three-year exclusivity covers only the modification for which the drug received approval on the basis of the new clinical investigations and does not prohibit the FDA from approving ANDAs or 505(b)(2) NDAs for drugs containing the active agent for the original indication or condition of use. Five-year and three-year exclusivity will not delay the submission or approval of a full NDA. However, an applicant submitting a full NDA would be required to conduct or obtain a right of
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reference to any preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and effectiveness.
Pediatric exclusivity is another type of marketing exclusivity available in the United States. Pediatric exclusivity provides for an additional six (6) months of marketing exclusivity attached to another period of exclusivity if a sponsor conducts clinical trials in children in response to a written request from the FDA. The issuance of a written request does not require the sponsor to undertake the described clinical trials. In addition, orphan drug exclusivity, as described above, may offer a seven-year period of marketing exclusivity, except in certain circumstances.
Other Healthcare Laws
Pharmaceutical and medical device manufacturers are subject to additional healthcare regulation and enforcement by the federal government and by authorities in the states and foreign jurisdictions in which they conduct their business. Such laws include, without limitation, U.S. federal anti-kickback, fraud and abuse, false claims, consumer fraud, pricing reporting, data privacy and security, and transparency laws and regulations as well as similar foreign laws in the jurisdictions outside the U.S. Similar state and local laws and regulations may also restrict business practices in the pharmaceutical industry, such as state anti-kickback and false claims laws, which may apply to business practices, including but not limited to, research, distribution, sales and marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payors, including private insurers, or by patients themselves; state laws that require pharmaceutical companies to comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government, or otherwise restrict payments that may be made to healthcare providers and other potential referral sources; state laws and regulations that require drug manufacturers to file reports relating to pricing and marketing information; state and local laws which require tracking gifts and other remuneration and items of value provided to physicians, other healthcare providers and entities or that require the registration of pharmaceutical sales representatives; and state and local laws that require the registration of pharmaceutical sales representatives; and state and local laws governing the privacy and security of health information in some circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts. Violation of any of such laws or any other governmental regulations that apply may result in penalties, including, without limitation, significant administrative, civil and criminal penalties, damages, fines, additional reporting obligations and oversight if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws, the curtailment or restructuring of operations, exclusion from participation in governmental healthcare programs and imprisonment.
Coverage and Reimbursement
Sales of any pharmaceutical product depend, in part, on the extent to which such product will be covered by third-party payors, such as federal, state and foreign government healthcare programs, commercial insurance and managed healthcare organizations, and the level of reimbursement for such product by third-party payors. Significant uncertainty exists as to the coverage and reimbursement status of any newly approved product. Decisions regarding the extent of coverage and amount of reimbursement to be provided are made on a plan-by-plan basis. One third-party payor’s decision to cover a particular product does not ensure that other payors will also provide coverage for the product. As a result, the coverage determination process can require manufactures to provide scientific and clinical support for the use of a product to each payor separately and can be a time-consuming process, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance. For products administered under the supervision of a physician, obtaining coverage and adequate reimbursement may be particularly difficult because of the higher prices often associated with such drugs. Additionally, separate reimbursement for the product itself or the treatment or procedure in which the product is used may not be available, which may impact physician utilization. In addition, companion diagnostic tests require coverage and reimbursement separate and apart from the coverage and reimbursement for their companion pharmaceutical or biological products. Similar challenges to obtaining coverage and reimbursement, applicable to pharmaceutical or biological products, will apply to companion diagnostics.
In addition, third-party payors are increasingly reducing reimbursements for pharmaceutical products and services. The U.S. government and state legislatures have continued implementing cost-containment programs, including price controls, restrictions on coverage and reimbursement and requirements for substitution of generic products. Third-party payors are more and more challenging the prices charged, examining the medical necessity and reviewing the cost effectiveness of pharmaceutical products, in addition to questioning their safety and efficacy. Adoption of price controls and cost-containment measures, and adoption of more restrictive policies in jurisdictions with existing controls and measures, could further limit sales of any product. Decreases in third-party reimbursement for any product or a decision by a third-party payor not to cover a product could reduce physician usage and patient demand for the product.
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In international markets, reimbursement and healthcare payment systems vary significantly by country, and many countries have instituted price ceilings on specific products and therapies. For example, the European Union provides options for its member states to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. A member state may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. Pharmaceutical products may face competition from lower-priced products in foreign countries that have placed price controls on pharmaceutical products and may also compete with imported foreign products. Furthermore, there is no assurance that a product will be considered medically reasonable and necessary for a specific indication, will be considered cost-effective by third-party payors, that an adequate level of reimbursement will be established even if coverage is available or that the third-party payors’ reimbursement policies will not adversely affect the ability for manufacturers to sell products profitably.
Healthcare Reform
In the United States and certain foreign jurisdictions, there have been, and we expect there will continue to be, a number of legislative and regulatory changes to the healthcare system. In March 2010, the ACA was signed into law, which substantially changed the way healthcare is financed by both governmental and private insurers in the United States. By way of example, the ACA increased the minimum level of Medicaid rebates payable by manufacturers of brand name drugs from 15.1% to 23.1%; required collection of rebates for drugs paid by Medicaid managed care organizations; imposed a non-deductible annual fee on pharmaceutical manufacturers or importers who sell certain “branded prescription drugs” to specified federal government programs, implemented a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for drugs that are inhaled, infused, instilled, implanted, or injected; expanded eligibility criteria for Medicaid programs; created a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research, along with funding for such research; and established a Center for Medicare Innovation at CMS to test innovative payment and service delivery models to lower Medicare and Medicaid spending, potentially including prescription drug spending.
Since its enactment, there have been judicial, executive and Congressional challenges to certain aspects of the ACA. For example, in 2017, Congress enacted the Tax Act, which eliminated the tax-based shared responsibility payment imposed by the ACA on certain individuals who fail to maintain qualifying health coverage for all or part of a year that is commonly referred to as the “individual mandate.” In addition, the 2020 federal spending package permanently eliminated, effective January 1, 2020, the ACA-mandated “Cadillac” tax on high-cost employer-sponsored health coverage and, effective January 1, 2021, also eliminated the health insurer tax. On December 14, 2018, a Texas U.S. District Court Judge ruled that the individual mandate is a critical and inseverable feature of the ACA, and therefore, because it was repealed as part of the Tax Act, the remaining provisions of the ACA are invalid as well. On December 18, 2019, the U.S. Court of Appeals for the 5th Circuit ruled that the individual mandate was unconstitutional and remanded the case back to the District Court to determine whether the remaining provisions of the ACA are invalid as well. The U.S. Supreme Court is currently reviewing the case, although it is unclear when a decision will be made or how the Supreme Court will rule. In addition, there may be other efforts to challenge, repeal or replace the ACA. We are continuing to monitor any changes to the ACA that, in turn, may potentially impact our business in the future.
Other legislative changes have been proposed and adopted since the ACA was enacted, including aggregate reductions of Medicare payments to providers of 2% per fiscal year and reduced payments to several types of Medicare providers, which will remain in effect through 2030, with the exception of a temporary suspension from May 1, 2020 through March 31, 2021, absent additional congressional action. Moreover, there has recently been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed and enacted legislation designed, among other things, to bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs and reform government program reimbursement methodologies for pharmaceutical products. The likelihood of success of these and other measures proposed by the previous administration is unclear, particularly in light of the current administration. In addition, individual states in the United States have also become increasingly active in implementing regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures and, in some cases, mechanisms to encourage importation from other countries and bulk purchasing. Furthermore, there has been increased interest by third party payors and governmental authorities in reference pricing systems and publication of discounts and list prices.
FDA Approval and Regulation of Companion Diagnostics
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If safe and effective use of a therapeutic depends on an in vitro diagnostic, then the FDA generally will require approval or clearance of that diagnostic, known as a companion diagnostic, at the same time that the FDA approves the therapeutic product. In August 2014, the FDA issued final guidance clarifying the requirements that will apply to approval of therapeutic products and in vitro companion diagnostics. According to the guidance, if FDA determines that a companion diagnostic device is essential to the safe and effective use of a novel therapeutic product or indication, FDA generally will not approve the therapeutic product or new therapeutic product indication if the companion diagnostic device is not approved or cleared for that indication. Approval or clearance of the companion diagnostic device will ensure that the device has been adequately evaluated and has adequate performance characteristics in the intended population. The review of in vitro companion diagnostics in conjunction with the review of our therapeutic treatments for cancer will, therefore, likely involve coordination of review by the FDA’s Center for Drug Evaluation and Research and the FDA’s Center for Devices and Radiological Health Office of In Vitro Diagnostics and Radiological Health.
Under the FDCA, in vitro diagnostics, including companion diagnostics, are regulated as medical devices. In the United States, the FDCA and its implementing regulations, and other federal and state statutes and regulations govern, among other things, medical device design and development, preclinical and clinical testing, premarket clearance or approval, registration and listing, manufacturing, labeling, storage, advertising and promotion, sales and distribution, export and import, and post-market surveillance. Unless an exemption applies, diagnostic tests require marketing clearance or approval from the FDA prior to commercial distribution. The two (2) primary types of FDA marketing authorization applicable to a medical device are premarket notification, also called 510(k) clearance, and premarket approval, or PMA approval.
The PMA process, including the gathering of clinical and preclinical data and the submission to and review by the FDA, can take several years or longer. It involves a rigorous premarket review during which the applicant must prepare and provide the FDA with reasonable assurance of the device’s safety and effectiveness and information about the device and its components regarding, among other things, device design, manufacturing and labeling. PMA applications are subject to an application fee. In addition, PMAs for certain devices must generally include the results from extensive preclinical and adequate and well-controlled clinical trials to establish the safety and effectiveness of the device for each indication for which FDA approval is sought. In particular, for a diagnostic, a PMA application typically requires data regarding analytical and clinical validation studies. As part of the PMA review, the FDA will typically inspect the manufacturer’s facilities for compliance with the Quality System Regulation, or QSR, which imposes elaborate testing, control, documentation and other quality assurance requirements.
PMA approval is not guaranteed, and the FDA may ultimately respond to a PMA submission with a not approvable determination based on deficiencies in the application and require additional clinical trial or other data that may be expensive and time-consuming to generate and that can substantially delay approval. If the FDA’s evaluation of the PMA application is favorable, the FDA typically issues an approvable letter requiring the applicant’s agreement to specific conditions, such as changes in labeling, or specific additional information, such as submission of final labeling, in order to secure final approval of the PMA. If the FDA’s evaluation of the PMA or manufacturing facilities is not favorable, the FDA will deny approval of the PMA or issue a not approvable letter. A not approvable letter will outline the deficiencies in the application and, where practical, will identify what is necessary to make the PMA approvable. The FDA may also determine that additional clinical trials are necessary, in which case the PMA approval may be delayed for several months or years while the trials are conducted and then the data submitted in an amendment to the PMA. If the FDA concludes that the applicable criteria have been met, the FDA will issue a PMA for the approved indications, which can be more limited than those originally sought by the applicant. The PMA can include post-approval conditions that the FDA believes necessary to ensure the safety and effectiveness of the device, including, among other things, restrictions on labeling, promotion, sale and distribution. Once granted, PMA approval may be withdrawn by the FDA if compliance with post approval requirements, conditions of approval or other regulatory standards are not maintained or problems are identified following initial marketing.
After a device is placed on the market, it remains subject to significant regulatory requirements. Medical devices may be marketed only for the uses and indications for which they are cleared or approved. Device manufacturers must also establish registration and device listings with the FDA. A medical device manufacturer’s manufacturing processes and those of its suppliers are required to comply with the applicable portions of the QSR, which cover the methods and documentation of the design, testing, production, processes, controls, quality assurance, labeling, packaging and shipping of medical devices. Domestic facility records and manufacturing processes are subject to periodic unscheduled inspections by the FDA. The FDA also may inspect foreign facilities that export products to the United States.




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Environmental, Social and Governance (ESG) Highlights
Social
Zentalis is committed to driving social impact through our therapeutics and operating in a way that is respectful and inclusive of all stakeholders. Below are a few initiatives that demonstrate our commitment to social impact:
We are committed to the safety and wellbeing of our employees and our stakeholders. Our employees receive rigorous annual trainings on general safety, on-site lab safety procedures, quality assurance and standard operating procedures (QA SOPs) to help ensure that we are managing risks and operating safely.
We are committed to being an equal opportunity employer and enhancing diversity and inclusion across our business. Our Code of Business Conduct and Ethics prohibits discrimination of any protected group and our employees participate in regular anti-harassment training, with managers receiving additional manager-specific anti-harassment training.
We are always working to enrich our diversity and inclusion, or D&I, strategies and performance, and we are proud of the gender diversity we have cultivated throughout the company and our management team. Over 44% of our VPs and above are female and 50% of our C-suite team is female. We intend to continue to develop our D&I practices and improve performance across our workforce.
We are dedicated to building a talented team and as such offer competitive compensation and comprehensive benefits to attract and retain top talent. In addition to offering benefits such as medical, dental, vision, 401(k) with company matching, flexible spending for healthcare and dependent care, life insurance and both short and long-term disability, we offer work / life balance benefits and employee development opportunities. These include flexible time off (vacation, sick leave, company shutdown during the holiday season), voluntary life-illness-accident insurance, wellness challenges and healthy food options onsite. We also have a variety of company-wide events to support camaraderie and encourage teamwork and collaboration.
In 2021, we expect to commence the first offering period under the Zentalis Pharmaceuticals, Inc. 2020 Employee Stock Purchase Plan for all full-time employees –a benefit we are proud to offer and that we believe will help to foster our corporate culture and encourage collaboration towards our shared business success.
In an effort to ensure the safety of our staff and clinical patients during the COVID-19 pandemic, we have closed our corporate offices in New York City temporarily and have been operating our labs in San Diego on rotational schedules to maintain proper social distancing while keeping our science and discovery work on track.
In 2020, we launched several new benefits for our employees to ease the transition to working from home during the COVID-19 pandemic including flexible work arrangements, supplementary time off and communications to help ensure employees felt cared for and supported both at home and at work.

Human Capital Management
As of December 31, 2020, Zentalis had 124 full-time employees, all of whom are based in the United States. Our workforce is highly skilled, with 34% of our employees holding an MD, PhD, or PharmD degree. Of these full-time employees, 84 employees are engaged in research and development activities. None of these employees are represented by labor unions or covered by any collective bargaining agreements.

Zentalis relies on skilled, innovative, and passionate employees to conduct our research, development and business activities. The biopharmaceutical industry is very competitive and recruiting and retaining employees is critical to the continued success of our business. To attract, maintain and motivate our team of ambitious professionals, we offer competitive compensation and benefits, a collaborative work environment, ongoing skills development initiatives, attractive career advancement opportunities, and a culture that values D&I. At Zentalis, everyone’s voice is heard, the work is meaningful, and employees are encouraged to think outside of the box.

Environmental
Zentalis is committed to minimizing the environmental impacts of our business, with the goal of being “green chemists,” applying our science in the labs carefully to efficiently use and conserve precious recourses. We encourage all employees to reduce waste and emissions through recycling and other energy conservation measures. Here are a few of the initiatives that demonstrate our commitment to environmental impact:
We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and waste.
We dispose of all hazardous materials and waste in a responsible manner; following strict protocols for the storage, treatment and disposal of hazardous, flammable, chemical or biological waste.
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Our employees are required to promptly report any known or suspected violations of environmental laws or any events that may result in a discharge or emission of hazardous materials.
We have recycling in all facilities for both regular recyclables and lab waste.

Governance
Zentalis is committed to strong governance systems and policies that ensure fair, transparent and efficient business practices. Here are a few initiatives that demonstrate our commitment to good governance:
Our board of directors and executive management team have oversight of all the relevant ESG issues that we have outlined in this section.
Our approaches to cybersecurity and privacy are overseen by our Chief Information Security Officer.
We have employee trainings, procedures and policies in place to ensure data privacy. These measures are outlined in our data privacy policy. We also have employee trainings, procedures and policies in place regarding cybersecurity. Trainings take place at regular intervals during our Company-wide meetings, and cover threats and phishing risk. We also have a defined information security incident response plan that supports Zentalis in the management of cyber security incidents.
We have adopted a Code of Business Conduct and Ethics with regular trainings and provisions related to corporate ethics, bribery and corruption, whistleblower policies, political involvement and other dimensions of corporate ethics.

Additional Information
We were initially formed as Zeno Pharmaceuticals, Inc., a Delaware corporation, in December 2014. In conjunction with a corporate restructuring, Zeno Pharma, LLC, a Delaware limited liability company, was formed, and in December 2017 acquired Zeno Pharmaceuticals, Inc., pursuant to a merger agreement. As a result of this acquisition, Zeno Pharmaceuticals, Inc. became a wholly-owned subsidiary of Zeno Pharma, LLC. In December 2019, Zeno Pharma, LLC changed its name to Zentalis Pharmaceuticals, LLC. In April 2020, in connection with our IPO, we converted to a Delaware corporation pursuant to a statutory conversion and changed our name to Zentalis Pharmaceuticals, Inc.

Our Internet address is www.zentalis.com. At our investor relations website, ir.zentalis.com, we make available free of charge a variety of information for investors, including our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and any amendments to those reports, as soon as reasonably practicable after we electronically file that material with or furnish it to the SEC. The information found on our website is not part of this Annual Report on Form 10-K or any other report we file with, or furnish to, the SEC.
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Item 1A. Risk Factors
You should carefully consider the risks and uncertainties described below and the other information in this Annual Report on Form 10-K, including our consolidated financial statements and related notes appearing elsewhere in this Annual Report on Form 10-K and in the section titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” before deciding whether to invest in our common stock. Such risks and uncertainties may be amplified by the COVID-19 pandemic and its potential impact on our business and the global economy. Our business, financial condition, results of operations or prospects could be materially and adversely affected if any of these risks occurs, and as a result, the market price of our common stock could decline and you could lose all or part of your investment. This Annual Report on Form 10-K also contains forward-looking statements that involve risks and uncertainties. See “Cautionary Note Regarding Forward-Looking Statements.” Additional risks and uncertainties not presently known to us or that we currently deem immaterial also may impair our business operations. Our actual results could differ materially and adversely from those anticipated in these forward-looking statements as a result of certain important factors, including those set forth below.
Risks Related to Our Financial Position and Need for Additional Capital
We have a limited operating history, have not completed any clinical trials, and have no products approved for commercial sale, which may make it difficult for you to evaluate our current business and predict our future success and viability.
We are a clinical stage biopharmaceutical company with a limited operating history upon which you can evaluate our business and prospects. We have no products approved for commercial sale and have not generated any revenue from product sales. To date, we have devoted substantially all of our resources and efforts to organizing and staffing our company, business planning, executing partnerships, raising capital, discovering, identifying and developing potential product candidates, securing related intellectual property rights and conducting preclinical studies and clinical trials of our product candidates, including the ongoing clinical trials of ZN-c5, ZN-c3 and ZN-e4. We have not yet demonstrated our ability to successfully complete any clinical trials, obtain marketing approvals, manufacture a commercial-scale product or arrange for a third party to do so on our behalf, or conduct sales and marketing activities necessary for successful product commercialization. As a result, it may be more difficult for you to accurately predict our future success or viability than it could be if we had a longer operating history.
In addition, we may encounter unforeseen expenses, difficulties, complications, delays and other known and unknown factors and risks frequently experienced by clinical stage biopharmaceutical companies in rapidly evolving fields. We also may need to transition from a company with a research focus to a company capable of supporting commercial activities. If we do not adequately address these risks and difficulties or successfully make such a transition, our business will suffer.
We have incurred significant net losses since inception and we expect to continue to incur significant net losses for the foreseeable future.
We have incurred net losses in each reporting period since our inception, have not generated any revenue from product sales to date and have financed our operations principally through private financings and our IPO. We have incurred net losses of $118.5 million and $46.4 million for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, we had an accumulated deficit of $200.8 million. Our losses have resulted principally from expenses incurred in research and development of our product candidates and from management and administrative costs and other expenses that we have incurred while building our business infrastructure. Three (3) of our product candidates, ZN-c5, ZN-c3 and ZN-e4, are in clinical trials, and we intend to initiate a Phase 1 clinical trial of ZN-d5 in patients with AML or B-cell lymphoma in the first half of 2021. In addition, we plan to submit an IND to the FDA for our fifth product candidate in 2021. Our other programs are in preclinical research. As a result, we expect that it will be several years, if ever, before we have a commercialized product and generate revenue from product sales. Even if we succeed in receiving marketing approval for and commercializing one or more of our product candidates, we expect that we will continue to incur substantial research and development and other expenses as we discover, develop and market additional potential products.
We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future as we continue our research and development efforts and seek to obtain regulatory approval and commercialization of our product candidates. The net losses we incur may fluctuate significantly from quarter to quarter such that a period-to-period comparison of our results of operations may not be a good indication of our future performance. The size of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenue. Our prior losses and expected future losses have had and will continue to have an adverse effect on our working capital and our ability to achieve and maintain profitability.
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Our ability to generate revenue and achieve profitability depends significantly on our ability to achieve a number of objectives.
Our business depends entirely on the successful discovery, development and commercialization of our product candidates. We currently generate no revenues from sales of any products. We have no products approved for commercial sale and do not anticipate generating any revenue from product sales for the next several years, if ever. Our ability to generate revenue and achieve profitability depends significantly on our ability, or any future collaborator’s ability, to achieve a number of objectives, including:
 
successful and timely completion of preclinical and clinical development of our product candidates, including ZN-c5, ZN-c3, ZN-d5 and ZN-e4 and any other future product candidates, as well as the associated costs, including any unforeseen costs we have incurred and may continue to incur as a result of preclinical study or clinical trial delays due to the COVID-19 pandemic or other causes;
establishing and maintaining relationships with contract research organizations, or CROs, and clinical sites for the clinical development, both in the United States and internationally, of our product candidates, including ZN-c5, ZN-c3, ZN-d5 and ZN-e4 and any other future product candidates;
timely receipt of marketing approvals from applicable regulatory authorities for any product candidates for which we successfully complete clinical development;
making any required post-marketing approval commitments to applicable regulatory authorities;
developing an efficient and scalable manufacturing process for our product candidates, including obtaining finished products that are appropriately packaged for sale;
establishing and maintaining commercially viable supply and manufacturing relationships with third parties that can provide adequate, in both amount and quality, products and services to support clinical development and meet the market demand for product candidates that we develop, if approved;
successful commercial launch following any marketing approval, including the development of a commercial infrastructure, whether in-house or with one or more collaborators;
a continued acceptable safety profile following any marketing approval of our product candidates;
commercial acceptance of our product candidates by patients, the medical community and third-party payors;
identifying, assessing and developing new product candidates;
obtaining, maintaining and expanding patent protection, trade secret protection and regulatory exclusivity, both in the United States and internationally;
protecting our rights in our intellectual property portfolio;
defending against third-party interference or infringement claims, if any;
negotiating favorable terms in any collaboration, licensing or other arrangements that may be necessary or desirable to develop, manufacture or commercialize our product candidates;
obtaining coverage and adequate reimbursement by hospitals, government and third-party payors for product candidates that we develop;
addressing any competing therapies and technological and market developments; and
attracting, hiring and retaining qualified personnel.
We may never be successful in achieving our objectives and, even if we do, may never generate revenue that is significant or large enough to achieve profitability. If we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would decrease the value of our company and could impair our ability to maintain or further our research and development efforts, raise additional necessary capital, grow our business and continue our operations.
We will require substantial additional capital to finance our operations. If we are unable to raise such capital when needed, or on acceptable terms, we may be forced to delay, reduce and/or eliminate one or more of our research and drug development programs or future commercialization efforts.
Developing pharmaceutical products, including conducting preclinical studies and clinical trials, is a very time-consuming, expensive and uncertain process that takes years to complete. Our operations have consumed substantial amounts of cash since inception, and we expect our expenses to increase in connection with our ongoing activities, particularly as we initiate and conduct clinical trials of, and seek marketing approval for, ZN-c5, ZN-c3, ZN-d5, ZN-e4 and our other product candidates. Even if one or more of the product candidates that we develop is approved for commercial sale, we anticipate incurring significant costs associated with commercializing any approved product candidate. Our expenses could increase beyond expectations if we are required by the FDA, the European Medicines Agency, or the EMA, or other regulatory agencies to perform clinical trials or preclinical studies in addition to those that we currently anticipate. Other unanticipated costs may also arise. In addition, if we obtain marketing approval for any of our product candidates, including ZN-c5, ZN-c3, ZN-d5 and ZN-e4, we expect to incur significant commercialization expenses related to drug sales, marketing, manufacturing and
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distribution. Because the design and outcome of our planned and anticipated clinical trials are highly uncertain, we cannot reasonably estimate the actual amounts necessary to successfully complete the development and commercialization of any product candidate we develop. We have also incurred, and expect to continue to incur additional costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in order to maintain our continuing operations.
As of December 31, 2020, we had cash, cash equivalents and marketable securities of $338.5 million. Based on current business plans, we believe that our existing cash, cash equivalents and marketable securities as of December 31, 2020 will be sufficient to fund our operating expenses and capital expenditures requirements into 2023, but will not be sufficient to fund all of the activities that are necessary to complete the development of our product candidates. This estimate is based on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently expect. Changing circumstances, some of which may be beyond our control, could cause us to consume capital significantly faster than we currently anticipate, and we may need to seek additional funds sooner than planned.
We will be required to obtain further funding through public or private equity offerings, debt financings, collaborations and licensing arrangements or other sources, which may dilute our stockholders or restrict our operating activities. We do not have any committed external source of funds. Adequate additional financing may not be available to us on acceptable terms, or at all. Market volatility resulting from the COVID-19 pandemic or other factors could also adversely impact our ability to access capital as and when needed. Our failure to raise capital as and when needed or on acceptable terms would have a negative impact on our financial condition and our ability to pursue our business strategy, and we may have to delay, reduce the scope of, suspend or eliminate one or more of our research-stage programs, clinical trials or future commercialization efforts.
Risks Related to the Discovery, Development and Commercialization of Our Product Candidates
We are substantially dependent on the success of our lead product candidates, ZN-c5 and/or ZN-c3, which are currently in clinical trials. If we are unable to complete development of, obtain approval for and commercialize these product candidates in a timely manner, our business will be harmed.
Our future success is dependent on our ability to timely complete clinical trials, obtain marketing approval for and successfully commercialize our lead product candidates. We are investing significant efforts and financial resources in the research and development of ZN-c5 and ZN-c3. ZN-c5 and ZN-c3 will require additional clinical development, evaluation of clinical, preclinical and manufacturing activities, marketing approval from government regulators, substantial investment and significant marketing efforts before we can generate any revenues from product sales. We are not permitted to market or promote ZN-c5 or ZN-c3, or any other product candidate, before we receive marketing approval from the FDA and comparable foreign regulatory authorities, and we may never receive such marketing approvals.
The success of our lead product candidates will depend on several factors, including the following:
 
the successful and timely completion of our ongoing clinical trials of ZN-c5 and ZN-c3;
the initiation and successful patient enrollment and completion of additional clinical trials of ZN-c5 and ZN-c3 on a timely basis;
maintaining and establishing relationships with CROs and clinical sites for the clinical development of ZN-c5 and ZN-c3 both in the United States and internationally;
the frequency and severity of adverse events in the clinical trials;
the efficacy, safety and tolerability profiles that are satisfactory to the FDA, EMA or any comparable foreign regulatory authority for marketing approval;
the timely receipt of marketing approvals for ZN-c5 and ZN-c3 from applicable regulatory authorities;
the extent of any required post-marketing approval commitments to applicable regulatory authorities;
the maintenance of existing or the establishment of new supply arrangements with third-party drug product suppliers and manufacturers for clinical development of ZN-c5 and ZN-c3;
the maintenance of existing, or the establishment of new, scaled production arrangements with third-party manufacturers to obtain finished products that are appropriate for commercial sale of ZN-c5 and ZN-c3 if approved, including for supplies of drugs that we are testing in combination with ZN-c5 and ZN-c3;
obtaining and maintaining patent protection, trade secret protection and regulatory exclusivity, both in the United States and internationally;
the protection of our rights in our intellectual property portfolio;
the successful launch of commercial sales following any marketing approval;
a continued acceptable safety profile following any marketing approval;
commercial acceptance by patients, the medical community and third-party payors; and
our ability to compete with other therapies.
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We do not have complete control over many of these factors, including certain aspects of clinical development and the regulatory submission process, potential threats to our intellectual property rights and the manufacturing, marketing, distribution and sales efforts of any future collaborator. If we are not successful with respect to one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully commercialize ZN-c5 and ZN-c3, which would materially harm our business. If we do not receive marketing approvals for ZN-c5 and ZN-c3, we may not be able to continue our operations.
We expect to depend on collaborations with third parties for the research, development and commercialization of certain of the product candidates we may develop. If any of these collaborations are not successful, we may not be able to capitalize on the market potential of those product candidates.
We anticipate seeking third-party collaborators for the research, development and commercialization of some of our product candidates. Our likely collaborators in any future collaboration arrangements we may enter into include large and mid-size pharmaceutical companies and biotechnology companies. If we were to enter into any collaboration arrangements with third parties, those agreements may limit our control over the amount and timing of resources that our collaborators dedicate to the development and commercialization of any product candidates we may seek to develop with them. We cannot predict the success of any collaboration in which we have entered or may enter.
Collaborations involving our research programs or any product candidates we may develop pose the following risks to us:
Collaborators have significant discretion in determining the efforts and resources that they will apply to these collaborations.
Collaborators may not pursue development and commercialization of any product candidates we may develop or may elect not to continue or renew development or commercialization programs based on clinical trial results, changes in the collaborator's strategic focus or market considerations or available funding or external factors such as an acquisition or business combination that diverts resources or creates competing priorities. If this were to happen, we may need additional capital to pursue further development or commercialization of the applicable product candidates.
Collaborators may delay clinical trials, provide insufficient funding for a clinical trial program, stop a clinical trial or abandon a product candidate, repeat or conduct new clinical trials or require a new formulation of a product candidate for clinical testing.
Collaborators could independently develop, or develop with third parties, products that compete directly or indirectly with our products or product candidates if the collaborators believe that competitive products are more likely to be successfully developed or can be commercialized under terms that are more economically attractive than ours.
Subject to certain diligence obligations, collaborators with marketing and distribution rights to one (1) or more products may not commit sufficient resources to the marketing and distribution of such product or products.
Collaborators may not properly obtain, maintain, enforce or defend our intellectual property or proprietary rights or may use proprietary information in a way that could jeopardize or invalidate our proprietary information or expose us to potential litigation.
Collaborators may own or co-own intellectual property covering our products that results from our collaborating with them, and in cases where that applies, we would not have the exclusive right to commercialize the collaboration intellectual property.
Disputes may arise between our collaborators and us that result in the delay or termination of the research, development or commercialization of our products or product candidates or that result in costly litigation or arbitration that diverts management attention and resources.
We may lose certain valuation rights under circumstances identified in our collaborations, including if we undergo a change of control.
Collaborations may be terminated and, if terminated, may result in a need for additional capital to pursue further development or commercialization of the applicable product candidates.
Collaboration agreements may not lead to development or commercialization of product candidates in the most efficient manner or at all. If a present or future collaborator of ours were to be involved in a business combination, the continued pursuit and emphasis on our product development or commercialization program under such collaboration could be delayed, diminished or terminated.
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Collaborators may be unable to maintain compliance with GLP and GCP requirements or to secure approval for clinical development plans from the FDA or foreign regulatory authorities.
If we do not receive the funding we expect under these agreements, our development of product candidates could be delayed and we may need additional resources to develop our product candidates. In addition, if one of our collaborators terminates its agreement with us, we may find it more difficult to find a suitable replacement collaborator or attract new collaborators and our development programs may be delayed or the perception of us in the business and financial communities could be adversely affected. All of the risks relating to product development, marketing approval and commercialization described in this annual report apply to the activities of our collaborators.
We may in the future decide to collaborate with pharmaceutical and biotechnology companies for the development and potential commercialization of any product candidates we may develop. These and other similar relationships may require us to incur non-recurring and other charges, increase our near- and long-term expenditures, issue securities that dilute our existing stockholders or disrupt our management and business. In addition, we could face significant competition in seeking appropriate collaborators and the negotiation process is time-consuming and complex. Our ability to reach a definitive collaboration agreement will depend, among other things, upon our assessment of the collaborator's resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator's evaluation of several factors. If we license rights to any product candidates we or our collaborators may develop, we may not be able to realize the benefit of those transactions if we are unable to successfully integrate them with our existing operations and company culture.

There is currently no FDA-approved oral SERD, and our development of ZN-c5 may never lead to a marketable product.
We are developing ZN-c5 as an oral SERD. There is currently no FDA-approved oral SERD. We have not received regulatory approval for ZN-c5 and cannot be certain that our approach will lead to the development of an approvable or marketable product, alone or in combination with other therapies. We may not succeed in demonstrating safety and efficacy of ZN-c5 in our ongoing Phase 1/2 clinical trial or in larger-scale clinical trials. Advancing ZN-c5 as an oral SERD creates significant challenges for us, including:
 
obtaining marketing approval, as the FDA, EMA or other regulatory authorities have never approved an orally available SERD;
if ZN-c5 is approved, educating medical personnel regarding the potential efficacy and safety benefits, as well as the challenges, of incorporating our ZN-c5 into existing treatment regimens, including in combination with other treatments for breast cancer; and
establishing the sales and marketing capabilities upon obtaining any marketing approvals to gain market acceptance.
Our long-term prospects depend in part upon discovering, developing and commercializing additional product candidates, which may fail in development or suffer delays that adversely affect their commercial viability.
Our future operating results are dependent on our ability to successfully discover, develop, obtain regulatory approval for and commercialize product candidates beyond those we currently have in clinical development. A product candidate can unexpectedly fail at any stage of preclinical and clinical development. The historical failure rate for product candidates is high due to risks relating to safety, efficacy, clinical execution, changing standards of medical care and other unpredictable variables. The results from preclinical testing or early clinical trials of a product candidate may not be predictive of the results that will be obtained in later stage clinical trials of the product candidate.
The success of other product candidates we may develop will depend on many factors, including the following:
 
generating sufficient data to support the initiation or continuation of clinical trials;
obtaining regulatory permission to initiate clinical trials;
contracting with the necessary parties to conduct clinical trials;
successful enrollment of patients in, and the completion of, clinical trials on a timely basis;
the timely manufacture of sufficient quantities of the product candidate for use in clinical trials; and
adverse events in the clinical trials.
Even if we successfully advance any other product candidates into clinical development, their success will be subject to all of the clinical, regulatory and commercial risks described elsewhere in this “Risk Factors” section. Accordingly, we cannot
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assure you that we will ever be able to discover, develop, obtain regulatory approval of, commercialize or generate significant revenue from our other product candidates.
The regulatory approval processes of the FDA, EMA and other comparable foreign regulatory authorities are lengthy, time consuming and inherently unpredictable. If we are ultimately unable to obtain regulatory approval for our product candidates, we will be unable to generate product revenue and our business will be substantially harmed.
We are not permitted to commercialize, market, promote or sell any product candidate in the United States without obtaining marketing approval from the FDA. Foreign regulatory authorities impose similar requirements. The time required to obtain approval by the FDA, EMA and other comparable foreign regulatory authorities is unpredictable, typically takes many years following the commencement of clinical trials and depends upon numerous factors, including the type, complexity and novelty of the product candidates involved. In addition, approval policies, regulations or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate’s clinical development and may vary among jurisdictions, which may cause delays in the approval or the decision not to approve an application. Regulatory authorities have substantial discretion in the approval process and may refuse to accept any application or may decide that our data are insufficient for approval and require additional preclinical, clinical or other data. Even if we eventually complete clinical testing and receive approval of any regulatory filing for our product candidates, the FDA, EMA and other comparable foreign regulatory authorities may approve our product candidates for a more limited indication or a narrower patient population than we originally requested. We have not submitted for, or obtained, regulatory approval for any product candidate, and it is possible that none of our existing product candidates or any product candidates we may seek to develop in the future will ever obtain regulatory approval.
Further, development of our product candidates and/or regulatory approval may be delayed for reasons beyond our control. For example, a U.S. federal government shutdown or budget sequestration, such as ones that occurred during 2013, 2018 and 2019, may result in significant reductions to the FDA’s budget, employees and operations, which may lead to slower response times and longer review periods, potentially affecting our ability to progress development of our product candidates or obtain regulatory approval for our product candidates.
Applications for our product candidates could fail to receive regulatory approval for many reasons, including the following:

the FDA, EMA or other comparable foreign regulatory authorities may disagree with the design, implementation or results of our clinical trials;
the FDA, EMA or other comparable foreign regulatory authorities may determine that our product candidates are not safe and effective, only moderately effective or have undesirable or unintended side effects, toxicities or other characteristics that preclude our obtaining marketing approval or prevent or limit commercial use;
the population studied in the clinical trial may not be sufficiently broad or representative to assure efficacy and safety in the full population for which we seek approval;
the FDA, EMA or other comparable foreign regulatory authorities may disagree with our interpretation of data from preclinical studies or clinical trials;
the data collected from clinical trials of our product candidates may not be sufficient to support the submission of a New Drug Application, or NDA, or other submission or to obtain regulatory approval in the United States or elsewhere;
we may be unable to demonstrate to the FDA, EMA or other comparable foreign regulatory authorities that a product candidate’s risk-benefit ratio for its proposed indication is acceptable;
the FDA, EMA or other comparable foreign regulatory authorities may fail to approve the manufacturing processes, test procedures and specifications or facilities of third-party manufacturers with which we contract for clinical and commercial supplies; and
the approval policies or regulations of the FDA, EMA or other comparable foreign regulatory authorities may significantly change in a manner rendering our clinical data insufficient for approval.

This lengthy approval process, as well as the unpredictability of the results of clinical trials, may result in our failing to obtain regulatory approval to market any of our product candidates, which would significantly harm our business, results of operations and prospects.
In addition, even if we obtain approval of our product candidates, regulatory authorities may approve any of our product candidates for fewer or more limited indications than we request, may impose significant limitations in the form of narrow indications, warnings, or a Risk Evaluation and Mitigation Strategy, or REMS. Regulatory authorities may not approve the price we intend to charge for products we may develop, may grant approval contingent on the performance of costly post-
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marketing clinical trials, or may approve a product candidate with a label that does not include the labeling claims necessary or desirable for the successful commercialization of that product candidate. Any of the foregoing scenarios could seriously harm our business.
The clinical trials of our product candidates may not demonstrate safety and efficacy to the satisfaction of the FDA, EMA or other comparable foreign regulatory authorities or otherwise produce positive results.
Before obtaining marketing approval from the FDA, EMA or other comparable foreign regulatory authorities for the sale of our product candidates, we must complete preclinical development and extensive clinical trials to demonstrate the safety and efficacy of our product candidates. Clinical testing is expensive, difficult to design and implement, can take many years to complete and its ultimate outcome is uncertain. A failure of one or more clinical trials can occur at any stage of the process. The outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their drugs. The outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their drugs.
In addition, we may rely in part on preclinical, clinical and quality data generated by CROs and other third parties for regulatory submissions for our product candidates. While we have or will have agreements governing these third parties’ services, we have limited influence over their actual performance. If these third parties do not make data available to us, or, if applicable, make regulatory submissions in a timely manner, in each case pursuant to our agreements with them, our development programs may be significantly delayed, and we may need to conduct additional studies or collect additional data independently. In either case, our development costs would increase.
We do not know whether our future clinical trials will begin on time or enroll patients on time, or whether our ongoing and/or future clinical trials will be completed on schedule or at all. Clinical trials can be delayed for a variety of reasons, including delays related to:
 
the FDA or comparable foreign regulatory authorities disagreeing as to the design or implementation of our clinical studies;
obtaining regulatory authorizations to commence a trial or reaching a consensus with regulatory authorities on trial design;
any failure or delay in reaching an agreement with CROs and clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different CROs and trial sites;
obtaining approval from one or more institutional review boards, or IRBs;
IRBs refusing to approve, suspending or terminating the trial at an investigational site, precluding enrollment of additional subjects, or withdrawing their approval of the trial;
changes to clinical trial protocol;
clinical sites deviating from trial protocol or dropping out of a trial;
manufacturing sufficient quantities of product candidate or obtaining sufficient quantities of combination therapies for use in clinical trials;
subjects failing to enroll or remain in our trial at the rate we expect, or failing to return for post-treatment follow-up;
subjects choosing an alternative treatment for the indication for which we are developing our product candidates, or participating in competing clinical trials;
lack of adequate funding to continue the clinical trial;
subjects experiencing severe or unexpected drug-related adverse effects;
occurrence of serious adverse events in trials of the same class of agents conducted by other companies;
selection of clinical end points that require prolonged periods of clinical observation or analysis of the resulting data;
a facility manufacturing our product candidates or any of their components being ordered by the FDA or comparable foreign regulatory authorities to temporarily or permanently shut down due to violations of current good manufacturing practice, or cGMP, regulations or other applicable requirements, or infections or cross-contaminations of product candidates in the manufacturing process;
any changes to our manufacturing process that may be necessary or desired;
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third-party clinical investigators losing the licenses or permits necessary to perform our clinical trials, not performing our clinical trials on our anticipated schedule or consistent with the clinical trial protocol, good clinical practices, or GCP, or other regulatory requirements;
third-party contractors not performing data collection or analysis in a timely or accurate manner; or
third-party contractors becoming debarred or suspended or otherwise penalized by the FDA or other government or regulatory authorities for violations of regulatory requirements, in which case we may need to find a substitute contractor, and we may not be able to use some or all of the data produced by such contractors in support of our marketing applications.
In addition, disruptions caused by the COVID-19 pandemic have caused and we expect will continue to cause difficulties or delays in initiating, enrolling, conducting or completing our planned and ongoing clinical trials. We could also encounter delays if a clinical trial is suspended or terminated by us, by the IRBs of the institutions in which such trials are being conducted, by a Data Safety Monitoring Board for such trial or by the FDA or comparable foreign regulatory authorities. Such authorities may impose such a suspension or termination due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA or comparable foreign regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. In addition, changes in regulatory requirements and policies may occur, and we may need to amend clinical trial protocols to comply with these changes. Amendments may require us to resubmit our clinical trial protocols to IRBs for reexamination, which may impact the costs, timing or successful completion of a clinical trial.
Further, conducting clinical trials in foreign countries, as we may do for our product candidates, presents additional risks that may delay completion of our clinical trials. These risks include the failure of enrolled patients in foreign countries to adhere to clinical protocol as a result of differences in healthcare services or cultural customs, managing additional administrative burdens associated with foreign regulatory schemes, as well as political and economic risks relevant to such foreign countries.
Moreover, principal investigators for our clinical trials may serve as scientific advisors or consultants to us from time to time and receive compensation in connection with such services. Under certain circumstances, we may be required to report some of these relationships to the FDA or comparable foreign regulatory authorities. The FDA or comparable foreign regulatory authority may conclude that a financial relationship between us and a principal investigator has created a conflict of interest or otherwise affected interpretation of the study. The FDA or comparable foreign regulatory authority may therefore question the integrity of the data generated at the applicable clinical trial site and the utility of the clinical trial itself may be jeopardized. This could result in a delay in approval, or rejection, of our marketing applications by the FDA or comparable foreign regulatory authority, as the case may be, and may ultimately lead to the denial of marketing approval of one or more of our product candidates.
If we experience delays in the completion of, or termination of, any clinical trial of our product candidates, the commercial prospects of our product candidates will be harmed, and our ability to generate product revenues from any of these product candidates will be delayed. Moreover, any delays in completing our clinical trials will increase our costs, slow down our product candidate development and approval process and jeopardize our ability to commence product sales and generate revenues.
In addition, many of the factors that cause, or lead to, termination or suspension of, or a delay in the commencement or completion of, clinical trials may also ultimately lead to the denial of regulatory approval of a product candidate. Any delays to our clinical trials that occur as a result could shorten any period during which we may have the exclusive right to commercialize our product candidates and our competitors may be able to bring products to market before we do, and the commercial viability of our product candidates could be significantly reduced. Any of these occurrences may harm our business, financial condition and prospects significantly.
The outcome of preclinical testing and early clinical trials may not be predictive of the success of later clinical trials, and the results of our clinical trials may not satisfy the requirements of the FDA, EMA or other comparable foreign regulatory authorities.
Before obtaining regulatory approvals for the commercial sale of any of our product candidates, we will be required to demonstrate with substantial evidence through well-controlled clinical trials that our product candidates are safe and effective for their intended uses. Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical trial process. Success in preclinical studies and early-stage clinical trials does not mean that future clinical trials will be successful. We do not know whether ZN-c5, ZN-c3, ZN-d5 and ZN-e4 will
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perform in current or future clinical trials as ZN-c5, ZN-c3, ZN-d5 and ZN-e4 have performed in preclinical studies, or, with respect to ZN-c5, ZN-c3 and ZN-e4, ongoing clinical trials to date. Product candidates in later-stage clinical trials may fail to demonstrate sufficient safety and efficacy to the satisfaction of the FDA, EMA and other comparable foreign regulatory authorities despite having progressed through preclinical studies and early-stage clinical trials.
In some instances, there can be significant variability in safety and efficacy results between different clinical trials of the same product candidate due to numerous factors, including changes in trial protocols, differences in size and type of the patient populations, differences in and adherence to the dosing regimen and other trial protocols and the rate of dropout among clinical trial participants. Patients treated with our product candidates may also be undergoing surgical, radiation and chemotherapy treatments and may be using other approved products or investigational new drugs, which can cause side effects or adverse events that are unrelated to our product candidate. As a result, assessments of efficacy can vary widely for a particular patient, and from patient to patient and site to site within a clinical trial. This subjectivity can increase the uncertainty of, and adversely impact, our clinical trial outcomes. We do not know whether any clinical trials we may conduct will demonstrate consistent or adequate efficacy and safety sufficient to obtain marketing approval to market our product candidates. Most product candidates that begin clinical trials are never approved by regulatory authorities for commercialization.
We have limited experience in designing clinical trials and may be unable to design and execute a clinical trial to support marketing approval. We cannot be certain that our planned clinical trials or any other future clinical trials will be successful. Additionally, any safety concerns observed in any one of our clinical trials in our targeted indications could limit the prospects for regulatory approval of our product candidates in those and other indications, which could seriously harm our business.
Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses and many companies that believed their product candidates performed satisfactorily in preclinical studies and clinical trials nonetheless failed to obtain FDA, EMA or comparable foreign regulatory authority approval. We cannot guarantee that the FDA or foreign regulatory authorities will interpret trial results as we do, and more trials could be required before we are able to submit applications seeking approval of our product candidates. To the extent that the results of the trials are not satisfactory to the FDA or foreign regulatory authorities for support of a marketing application, we may be required to expend significant resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates. Even if regulatory approval is secured for any of our product candidates, the terms of such approval may limit the scope and use of our product candidate, which may also limit its commercial potential. Furthermore, the approval policies or regulations of the FDA, EMA or comparable foreign regulatory authorities may significantly change in a manner rendering our clinical data insufficient for approval, which may lead to the FDA, EMA or comparable foreign regulatory authorities delaying, limiting or denying approval of our product candidates.
Interim, initial, “topline”, and preliminary data from our clinical trials that we announce or publish from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.
From time to time, we may publicly disclose preliminary or topline data from our preclinical studies and clinical trials, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. As a result, the topline or preliminary results that we report may differ from future results of the same studies, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated. Topline data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously published. As a result, topline data should be viewed with caution until the final data are available.
From time to time, we may also disclose interim data from our preclinical studies and clinical trials. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available or as patients from our clinical trials continue other treatments for their disease. Adverse differences between preliminary or interim data and final data could significantly harm our business prospects. Further, disclosure of interim data by us or by our competitors could result in volatility in the price of our common stock.
Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our company in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is based on what
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is typically extensive information, and you or others may not agree with what we determine is material or otherwise appropriate information to include in our disclosure.
If the interim, topline, or preliminary data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, our product candidates may be harmed, which could harm our business, operating results, prospects or financial condition.
Even if approved, our product candidates may not achieve adequate market acceptance among physicians, patients, healthcare payors and others in the medical community necessary for commercial success.
Even if our product candidates receive regulatory approval, they may not gain adequate market acceptance among physicians, patients, healthcare payors and others in the medical community. The degree of market acceptance of any of our approved product candidates will depend on a number of factors, including:
 
the efficacy and safety profile as demonstrated in clinical trials compared to alternative treatments;
the timing of market introduction of the product candidate as well as competitive products;
the clinical indications for which the product candidate is approved;
restrictions on the use of our product candidates, such as boxed warnings or contraindications in labeling, or a REMS, if any, which may not be required of alternative treatments and competitor products;
the potential and perceived advantages of product candidates over alternative treatments;
the cost of treatment in relation to alternative treatments;
the availability of coverage and adequate reimbursement, as well as pricing, by third-party payors, including government authorities;
the availability of the approved product candidate for use as a combination therapy;
relative convenience and ease of administration;
the willingness of the target patient population to try new therapies and of physicians to prescribe these therapies;
the effectiveness of sales and marketing efforts;
unfavorable publicity relating to our products or product candidates or similar approved products or product candidates in development by third parties; and
the approval of other new therapies for the same indications.
If any of our product candidates is approved but does not achieve an adequate level of acceptance by physicians, hospitals, healthcare payors and patients, we may not generate or derive sufficient revenue from that product candidate and our financial results could be negatively impacted.
If we experience delays or difficulties in the enrollment and/or maintenance of patients in clinical trials, our clinical development activities could be delayed or otherwise adversely affected.
Patient enrollment is a significant factor in the timing of clinical trials, and the timing of our clinical trials depends, in part, on the speed at which we can recruit patients to participate in our trials, as well as completion of required follow-up periods. We may not be able to initiate or continue clinical trials for our product candidates if we are unable to locate and enroll a sufficient number of eligible patients to participate in these trials to such trial’s conclusion as required by the FDA, EMA or other comparable foreign regulatory authorities. Additionally, certain clinical trials for future product candidates may be focused on indications with relatively small patient populations, which may further limit enrollment of eligible patients or may result in slower enrollment than we anticipate. The eligibility criteria of our clinical trials, once established, may further limit the pool of available trial participants.
Patient enrollment may also be affected if our competitors have ongoing clinical trials for product candidates that are under development for the same indications as our product candidates, and patients who would otherwise be eligible for our clinical trials instead enroll in clinical trials of our competitors’ product candidates. Patient enrollment for any of our clinical trials may be affected by other factors, including:
 
size and nature of the patient population;
severity of the disease under investigation;
availability and efficacy of approved drugs for the disease under investigation;
patient eligibility criteria for the trial in question as defined in the protocol;
perceived risks and benefits of the product candidate under study;
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clinicians’ and patients’ perceptions as to the potential advantages of the product candidate being studied in relation to other available therapies, including any new products that may be approved for the indications we are investigating;
efforts to facilitate timely enrollment in clinical trials;
patient referral practices of physicians;
the ability to monitor patients adequately during and after treatment;
proximity and availability of clinical trial sites for prospective patients;
continued enrollment of prospective patients by clinical trial sites; and
the risk that patients enrolled in clinical trials will drop out of the trials before completion or, because they may be late-stage cancer patients, will not survive the full terms of the clinical trials.
Our inability to enroll a sufficient number of patients for our clinical trials would result in significant delays or may require us to abandon one or more clinical trials altogether. Enrollment delays in our clinical trials may result in increased development costs for our product candidates and jeopardize our ability to obtain marketing approval for the sale of our product candidates. Furthermore, even if we are able to enroll a sufficient number of patients for our clinical trials, we may have difficulty maintaining enrollment of such patients in our clinical trials.
We intend to develop ZN-c5, ZN-c3, ZN-d5, ZN-e4 and potentially other product candidates in combination with other therapies, which exposes us to additional risks.
We intend to develop ZN-c5, ZN-c3, ZN-d5, ZN-e4 and likely other future product candidates in combination with one or more other approved or unapproved therapies to treat cancer or other diseases. For example, we are currently evaluating ZN-c5 in combination with certain approved agents, including palbociclib and abemaciclib.
Even if any product candidate we develop were to receive marketing approval or be commercialized for use in combination with other existing therapies, we would continue to be subject to the risks that the FDA, EMA or comparable foreign regulatory authorities outside of the United States could revoke approval of the therapy used in combination with our product or that safety, efficacy, manufacturing or supply issues could arise with any of those existing therapies. If the therapies we use in combination with our product candidates are replaced as the standard of care for the indications we choose for any of our product candidates, the FDA, EMA or comparable foreign regulatory authorities may require us to conduct additional clinical trials. The occurrence of any of these risks could result in our own products, if approved, being removed from the market or being less successful commercially.
We also may choose to evaluate ZN-c5, ZN-c3, ZN-d5, ZN-e4 or any other future product candidates in combination with one or more cancer therapies that have not yet been approved for marketing by the FDA, EMA or comparable foreign regulatory authorities. We will not be able to market and sell ZN-c5, ZN-c3, ZN-d5, ZN-e4 or any product candidate we develop in combination with an unapproved cancer therapy for a combination indication if that unapproved therapy does not ultimately obtain marketing approval either alone or in combination with our product. In addition, unapproved cancer therapies face the same risks described with respect to our product candidates currently in development and clinical trials, including the potential for serious adverse effects, delay in their clinical trials and lack of FDA approval.
If the FDA, EMA or comparable foreign regulatory authorities do not approve these other drugs or revoke their approval of, or if safety, efficacy, quality, manufacturing or supply issues arise with, the drugs we choose to evaluate in combination with our product candidate we develop, we may be unable to obtain approval of or market such combination therapy.
If the market opportunity for any product candidate that we or our strategic partners develop is smaller than we believe, our revenue may be adversely affected and our business may suffer.
We intend to initially focus our product candidate development on treatments for various oncology indications. Our projections of addressable patient populations that may benefit from treatment with our product candidates are based on our estimates. These estimates, which have been derived from a variety of sources, including scientific literature, surveys of clinics, patient foundations and market research, may prove to be incorrect. Further, new studies may change the estimated incidence or prevalence of these cancers. Additionally, the potentially addressable patient population for our product candidates may not ultimately be amenable to treatment with our product candidates. Our market opportunity may also be limited by future competitor treatments that enter the market. If any of our estimates prove to be inaccurate, the market opportunity for any product candidate that we or our strategic partners develop could be significantly diminished and have an adverse material impact on our business.
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We face significant competition, and if our competitors develop and market technologies or products more rapidly than we do or that are more effective, safer or less expensive than the product candidates we develop, our commercial opportunities will be negatively impacted.
The biotechnology and pharmaceutical industries are characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary and novel products and product candidates. Our competitors have developed, are developing or may develop products, product candidates and processes competitive with our product candidates. Any product candidates that we successfully develop and commercialize will compete with existing therapies and new therapies that may become available in the future. We believe that a significant number of products are currently under development, and may become commercially available in the future, for the treatment of conditions for which we may attempt to develop product candidates. In addition, our products may need to compete with off-label drugs used by physicians to treat the indications for which we seek approval. This may make it difficult for us to replace existing therapies with our products.
In particular, there is intense competition in the fields of oncology we are pursuing. We have competitors both in the United States and internationally, including major multinational pharmaceutical companies, established biotechnology companies, specialty pharmaceutical companies, emerging and start-up companies, universities and other research institutions. We also compete with these organizations to recruit management, scientists and clinical development personnel, which could negatively affect our level of expertise and our ability to execute our business plan. We will also face competition in establishing clinical trial sites, enrolling subjects for clinical trials and in identifying and in-licensing new product candidates.
We have chosen to initially address well-validated biochemical targets, and therefore expect to face competition from existing products and products in development for each of our product candidates. There are a large number of companies developing or marketing treatments for cancer, including many major pharmaceutical and biotechnology companies. Many of these current and potential competitors have significantly greater financial, manufacturing, marketing, drug development, technical and human resources and commercial expertise than we do. Large pharmaceutical and biotechnology companies, in particular, have extensive experience in clinical testing, obtaining regulatory approvals, recruiting patients and manufacturing biotechnology products. These companies also have significantly greater research and marketing capabilities than we do and may also have products that have been approved or are in late stages of development, and collaborative arrangements in our target markets with leading companies and research institutions. Established pharmaceutical and biotechnology companies may also invest heavily to accelerate discovery and development of novel compounds or to in-license novel compounds that could make the product candidates that we develop obsolete. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies, as well as in acquiring technologies complementary to, or necessary for, our programs. As a result of all of these factors, our competitors may succeed in obtaining approval from the FDA, EMA or other comparable foreign regulatory authorities or in discovering, developing and commercializing products in our field before we do.
Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe effects, are more convenient, have a broader label, are marketed more effectively, are reimbursed or are less expensive than any products that we may develop. Our competitors also may obtain marketing approval from the FDA, EMA or other comparable foreign regulatory authorities for their products more rapidly than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market. Even if the product candidates we develop achieve marketing approval, they may be priced at a significant premium over competitive products if any have been approved by then, resulting in reduced competitiveness. Technological advances or products developed by our competitors may render our technologies or product candidates obsolete, less competitive or not economical. If we are unable to compete effectively, our opportunity to generate revenue from the sale of our products we may develop, if approved, could be adversely affected.
We may expend our limited resources to pursue a particular product candidate or indication and fail to capitalize on product candidates or indications that may be more profitable or for which there is a greater likelihood of success.
Because we have limited financial and managerial resources, we focus on research programs, therapeutic platforms and product candidates that we identify for specific indications. As a result, we may forego or delay pursuit of opportunities with other therapeutic platforms or product candidates or for other indications that later prove to have greater commercial potential or a greater likelihood of success. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs, therapeutic platforms and product candidates for specific indications may not yield any commercially viable products. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that product candidate through collaboration, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights.
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Changes in methods of product candidate manufacturing or formulation may result in additional costs or delay.
As product candidates progress through preclinical and clinical trials to marketing approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods and formulation, are altered along the way in an effort to optimize yield and manufacturing batch size, minimize costs and achieve consistent quality and results. Such changes carry the risk that they will not achieve these intended objectives. Any of these changes could cause our product candidates to perform differently and affect the results of planned clinical trials or other future clinical trials conducted with the altered materials. This could delay completion of clinical trials, require the conduct of bridging clinical trials or the repetition of one or more clinical trials, increase clinical trial costs, delay approval of our product candidates and jeopardize our ability to commercialize our product candidates, if approved, and generate revenue.
Our business entails a significant risk of product liability and if we are unable to obtain sufficient insurance coverage such inability could have an adverse effect on our business and financial condition.
Our business exposes us to significant product liability risks inherent in the development, testing, manufacturing and marketing of therapeutic treatments. Product liability claims could delay or prevent completion of our development programs. If we succeed in marketing products, such claims could result in an FDA, EMA or other regulatory authority investigation of the safety and effectiveness of our products, our manufacturing processes and facilities or our marketing programs. FDA, EMA or other regulatory authority investigations could potentially lead to a recall of our products or more serious enforcement action, limitations on the approved indications for which they may be used or suspension or withdrawal of approvals. Regardless of the merits or eventual outcome, liability claims may also result in decreased demand for our products, injury to our reputation, costs to defend the related litigation, a diversion of management’s time and our resources and substantial monetary awards to trial participants or patients. We currently have product liability insurance that we believe is appropriate for our stage of development and may need to obtain higher levels prior to marketing any of our product candidates, if approved. Any insurance we have or may obtain may not provide sufficient coverage against potential liabilities. Furthermore, clinical trial and product liability insurance is becoming increasingly expensive. As a result, we may be unable to obtain sufficient insurance at a reasonable cost to protect us against losses caused by product liability claims that could have an adverse effect on our business and financial condition. Similar challenges to obtaining coverage and reimbursement, applicable to pharmaceutical or biological products, will apply to companion diagnostics that we or our collaborators may develop.
Any product candidates we develop may become subject to unfavorable third-party coverage and reimbursement practices, as well as pricing regulations.
The availability and extent of coverage and adequate reimbursement by third-party payors, including government health administration authorities, private health coverage insurers, managed care organizations and other third-party payors is essential for most patients to be able to afford expensive treatments. Sales of any of our product candidates that receive marketing approval will depend substantially, both in the United States and internationally, on the extent to which the costs of our product candidates will be covered and reimbursed by third-party payors. If reimbursement is not available, or is available only to limited levels, we may not be able to successfully commercialize our product candidates. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain pricing sufficient to realize an adequate return on our investment. Coverage and reimbursement may impact the demand for, or the price of, any product candidate for which we obtain marketing approval. If coverage and reimbursement are not available or reimbursement is available only to limited levels, we may not successfully commercialize any product candidate for which we obtain marketing approval.
There is significant uncertainty related to third-party payor coverage and reimbursement of newly approved products. In the United States, for example, principal decisions about reimbursement for new products are typically made by the Centers for Medicare & Medicaid Services, or CMS, an agency within the U.S. Department of Health and Human Services, or HHS. CMS decides whether and to what extent a new product will be covered and reimbursed under Medicare, and private third-party payors often follow CMS’s decisions regarding coverage and reimbursement to a substantial degree. However, one third-party payor’s determination to provide coverage for a product candidate does not assure that other payors will also provide coverage for the product candidate. As a result, the coverage determination process is often time-consuming and costly. This process will require us to provide scientific and clinical support for the use of our products to each third-party payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance.
Increasingly, third-party payors are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. Further, such payors are increasingly challenging the price, examining the medical necessity and reviewing the cost effectiveness of medical product candidates. There may be especially significant delays in obtaining coverage and reimbursement for newly approved drugs. Third-party payors may limit coverage
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to specific product candidates on an approved list, known as a formulary, which might not include all FDA-approved drugs for a particular indication. We may need to conduct expensive pharmaco-economic studies to demonstrate the medical necessity and cost effectiveness of our products. Nonetheless, our product candidates may not be considered medically necessary or cost effective. We cannot be sure that coverage and reimbursement will be available for any product that we commercialize and, if reimbursement is available, what the level of reimbursement will be.
Outside the United States, international operations are generally subject to extensive governmental price controls and other market regulations, and we believe the increasing emphasis on cost containment initiatives in Europe, Canada and other countries has and will continue to put pressure on the pricing and usage of therapeutics such as our product candidates. In many countries, particularly the countries of the European Union, medical product prices are subject to varying price control mechanisms as part of national health systems. In these countries, pricing negotiations with governmental authorities can take considerable time after a product receives marketing approval. To obtain reimbursement or pricing approval in some countries, we may be required to conduct a clinical trial that compares the cost-effectiveness of our product candidate to other available therapies. In general, product prices under such systems are substantially lower than in the United States. Other countries allow companies to fix their own prices for products, but monitor and control company profits. Additional foreign price controls or other changes in pricing regulation could restrict the amount that we are able to charge for our product candidates. Accordingly, in markets outside the United States, the reimbursement for our products may be reduced compared with the United States and may be insufficient to generate commercially reasonable revenue and profits.
If we are unable to establish or sustain coverage and adequate reimbursement for any future product candidates from third-party payors, the adoption of those products and sales revenue will be adversely affected, which, in turn, could adversely affect the ability to market or sell those product candidates, if approved. Coverage policies and third-party payor reimbursement rates may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future.
Risks Related to Regulatory Approval and Other Legal Compliance Matters
We may be unable to obtain U.S. or foreign regulatory approvals and, as a result, may be unable to commercialize our product candidates.
Our product candidates are subject to extensive governmental regulations relating to, among other things, research, testing, development, manufacturing, safety, efficacy, approval, recordkeeping, reporting, labeling, storage, packaging, advertising and promotion, pricing, marketing and distribution of drugs. Rigorous preclinical testing and clinical trials and an extensive regulatory approval process must be successfully completed in the United States and in many foreign jurisdictions before a new drug can be marketed. Satisfaction of these and other regulatory requirements is costly, time consuming, uncertain and subject to unanticipated delays. We cannot provide any assurance that any product candidate we may develop will progress through required clinical testing and obtain the regulatory approvals necessary for us to begin selling them.
We have not conducted, managed or completed large-scale or pivotal clinical trials nor managed the regulatory approval process with the FDA or any other regulatory authority. The time required to obtain approvals from the FDA and other regulatory authorities is unpredictable, and requires successful completion of extensive clinical trials which typically takes many years, depending upon the type, complexity and novelty of the product candidate. The standards that the FDA and its foreign counterparts use when evaluating clinical trial data can and often changes during drug development, which makes it difficult to predict with any certainty how they will be applied. We may also encounter unexpected delays or increased costs due to new government regulations, including future legislation or administrative action, or changes in FDA policy during the period of drug development, clinical trials and FDA regulatory review.
Any delay or failure in seeking or obtaining required approvals would have a material and adverse effect on our ability to generate revenue from the particular product candidate for which we developing and seeking approval. Furthermore, any regulatory approval to market a drug may be subject to significant limitations on the approved uses or indications for which we may market the drug or the labeling or other restrictions. In addition, the FDA has the authority to require a REMS as part of approving a NDA, or after approval, which may impose further requirements or restrictions on the distribution or use of an approved drug. These requirements or restrictions might include limiting prescribing to certain physicians or medical centers that have undergone specialized training, limiting treatment to patients who meet certain safe-use criteria and requiring treated patients to enroll in a registry. These limitations and restrictions may significantly limit the size of the market for the drug and affect reimbursement by third-party payors.
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We are also subject to numerous foreign regulatory requirements governing, among other things, the conduct of clinical trials, manufacturing and marketing authorization, pricing and third-party reimbursement. The foreign regulatory approval process varies among countries, and generally includes all of the risks associated with FDA approval described above as well as risks attributable to the satisfaction of local regulations in foreign jurisdictions. Moreover, the time required to obtain approval may differ from that required to obtain FDA approval.
Our current or future product candidates may cause significant adverse events, toxicities or other undesirable side effects when used alone or in combination with other approved products or investigational new drugs that may result in a safety profile that could inhibit regulatory approval, prevent market acceptance, limit their commercial potential or result in significant negative consequences.
As is the case with pharmaceuticals generally, it is likely that there may be side effects and adverse events associated with our product candidates’ use. Results of our clinical trials could reveal a high and unacceptable severity and prevalence of side effects or unexpected characteristics. Undesirable side effects caused by our product candidates could cause us or regulatory authorities to interrupt, delay or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or comparable foreign regulatory authorities. The drug-related side effects could affect patient recruitment or the ability of enrolled patients to complete the trial or result in potential product liability claims. Any of these occurrences may harm our business, financial condition and prospects significantly.
If our product candidates are associated with undesirable side effects or have unexpected characteristics in preclinical studies or clinical trials when used alone or in combination with other approved products or investigational new drugs we may need to interrupt, delay or abandon their development or limit development to more narrow uses or subpopulations in which the undesirable side effects or other characteristics are less prevalent, less severe or more acceptable from a risk-benefit perspective. Treatment-related side effects could also affect patient recruitment or the ability of enrolled subjects to complete the trial, or result in potential product liability claims. Any of these occurrences may prevent us from achieving or maintaining market acceptance of the affected product candidate and may harm our business, financial condition and prospects significantly.
Patients in our ongoing and planned clinical trials may in the future suffer significant adverse events or other side effects not observed in our preclinical studies or previous clinical trials. Some of our product candidates, may be used as chronic therapies or be used in pediatric populations, for which safety concerns may be particularly scrutinized by regulatory agencies. In addition, if our product candidates are used in combination with other therapies, our product candidates may exacerbate adverse events associated with the therapy. Patients treated with our product candidates may also be undergoing surgical, radiation and chemotherapy treatments, which can cause side effects or adverse events that are unrelated to our product candidate, but may still impact the success of our clinical trials. The inclusion of critically ill patients in our clinical trials may result in deaths or other adverse medical events due to other therapies or medications that such patients may be using or due to the gravity of such patients’ illnesses.
If significant adverse events or other side effects are observed in any of our current or future clinical trials, we may have difficulty recruiting patients to the clinical trials, patients may drop out of our trials, or we may be required to abandon the trials or our development efforts of that product candidate altogether. We, the FDA, EMA, other comparable regulatory authorities or an IRB may suspend clinical trials of a product candidate at any time for various reasons, including a belief that subjects in such trials are being exposed to unacceptable health risks or adverse side effects. Some potential therapeutics developed in the biotechnology industry that initially showed therapeutic promise in early-stage trials have later been found to cause side effects that prevented their further development. Even if the side effects do not preclude the product candidate from obtaining or maintaining marketing approval, undesirable side effects may inhibit market acceptance due to its tolerability versus other therapies. Any of these developments could materially harm our business, financial condition and prospects.
Further, if any of our product candidates obtains marketing approval, toxicities associated with such product candidates and not seen during clinical testing may also develop after such approval and lead to a requirement to conduct additional clinical safety trials, additional contraindications, warnings and precautions being added to the drug label, significant restrictions on the use of the product or the withdrawal of the product from the market. We cannot predict whether our product candidates will cause toxicities in humans that would preclude or lead to the revocation of regulatory approval based on preclinical studies or early-stage clinical trials.
The FDA, EMA and other comparable foreign regulatory authorities may not accept data from trials conducted in locations outside of their jurisdiction.
We may choose to conduct international clinical trials in the future. The acceptance of study data by the FDA, EMA or other comparable foreign regulatory authority from clinical trials conducted outside of their respective jurisdictions may be
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subject to certain conditions. In cases where data from foreign clinical trials are intended to serve as the basis for marketing approval in the United States, the FDA will generally not approve the application on the basis of foreign data alone unless (1) the data are applicable to the United States population and United States medical practice; (2) the trials are performed by clinical investigators of recognized competence and pursuant to current GCP requirements; and (3) the FDA is able to validate the data through an on-site inspection or other appropriate mean. Additionally, the FDA’s clinical trial requirements, including the adequacy of the patient population studied and statistical powering, must be met. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA, EMA or any applicable foreign regulatory authority will accept data from trials conducted outside of its applicable jurisdiction. If the FDA, EMA or any applicable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which would be costly and time-consuming and delay aspects of our business plan, and which may result in our product candidates not receiving approval for commercialization in the applicable jurisdiction.
Obtaining and maintaining regulatory approval of our product candidates in one jurisdiction does not mean that we will be successful in obtaining regulatory approval of our product candidates in other jurisdictions.
Obtaining and maintaining regulatory approval of our product candidates in one jurisdiction does not guarantee that we will be able to obtain or maintain regulatory approval in any other jurisdiction. For example, even if the FDA or EMA grants marketing approval of a product candidate, comparable regulatory authorities in foreign jurisdictions must also approve the manufacturing, marketing and promotion and reimbursement of the product candidate in those countries. However, a failure or delay in obtaining regulatory approval in one jurisdiction may have a negative effect on the regulatory approval process in others. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from those in the United States, including additional preclinical studies or clinical trials as clinical trials conducted in one jurisdiction may not be accepted by regulatory authorities in other jurisdictions. In many jurisdictions outside the United States, a product candidate must be approved for reimbursement before it can be approved for sale in that jurisdiction. In some cases, the price that we intend to charge for our products is also subject to approval.
Obtaining foreign regulatory approvals and establishing and maintaining compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our products in certain countries. If we or any future collaborator fail to comply with the regulatory requirements in international markets or fail to receive applicable marketing approvals, our target market will be reduced and our ability to realize the full market potential of our product candidates will be harmed.
Even if our product candidates receive regulatory approval, they will be subject to significant post-marketing regulatory requirements and oversight.
Any regulatory approvals that we may receive for our product candidates will require the submission of reports to regulatory authorities and surveillance to monitor the safety and efficacy of the product candidate, may contain significant limitations related to use restrictions for specified age groups, warnings, precautions or contraindications, and may include burdensome post-approval study or risk management requirements. For example, the FDA may require a REMS in order to approve our product candidates, which could entail requirements for a medication guide, physician training and communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. In addition, if the FDA or foreign regulatory authorities approve our product candidates, the manufacturing processes, labeling, packaging, distribution, adverse event reporting, storage, advertising, promotion, import, export and recordkeeping for our product candidates will be subject to extensive and ongoing regulatory requirements. These requirements include submissions of safety and other post-marketing information and reports, registration, as well as on-going compliance with cGMPs and GCP for any clinical trials that we conduct post-approval. In addition, manufacturers of drug products and their facilities are subject to continual review and periodic, unannounced inspections by the FDA and other regulatory authorities for compliance with cGMP regulations and standards. If we or a regulatory agency discover previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, or problems with the facilities where the product is manufactured, a regulatory agency may impose restrictions on that product, the manufacturing facility or us, including requiring recall or withdrawal of the product from the market or suspension of manufacturing. In addition, failure to comply with FDA, EMA and other comparable foreign regulatory requirements may subject our company to administrative or judicially imposed sanctions, including:
 
delays in or the rejection of product approvals;
restrictions on our ability to conduct clinical trials, including full or partial clinical holds on ongoing or planned trials;
restrictions on the products, manufacturers or manufacturing process;
warning or untitled letters;
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civil and criminal penalties;
injunctions;
suspension or withdrawal of regulatory approvals;
product seizures, detentions or import bans;
voluntary or mandatory product recalls and publicity requirements;
total or partial suspension of production; and
imposition of restrictions on operations, including costly new manufacturing requirements.
The occurrence of any event or penalty described above may inhibit our ability to commercialize our product candidates and generate revenue and could require us to expend significant time and resources in response and could generate negative publicity.
The FDA’s and other regulatory authorities’ policies may change, and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. We also cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. For example, the results of the 2020 U.S. Presidential Election may impact our business and industry. Namely, the previous administration took several executive actions, including the issuance of a number of Executive Orders, that could impose significant burdens on, or otherwise materially delay, the FDA's ability to engage in routine oversight activities such as implementing statutes through rulemaking, issuance of guidance, and review and approval of marketing applications. It is difficult to predict whether or how these orders will be implemented, or whether they will be rescinded and replaced under the current administration. The policies and priorities of the new administration are unknown and could materially impact the regulations governing our product candidates. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may be subject to enforcement action and we may not achieve or sustain profitability.
The FDA and other regulatory agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses.
If any of our product candidates are approved and we are found to have improperly promoted off-label uses of those products, we may become subject to significant liability. The FDA and other regulatory agencies strictly regulate the promotional claims that may be made about prescription products, such as our product candidates, if approved. In particular, a product may not be promoted for uses that are not approved by the FDA or such other regulatory agencies as reflected in the product’s approved labeling. If we receive marketing approval for a product candidate, physicians may nevertheless prescribe it to their patients in a manner that is inconsistent with the approved label. If we are found to have promoted such off-label uses, we may become subject to significant liability. The U.S. federal government has levied large civil and criminal fines against companies for alleged improper promotion of off-label use and has enjoined several companies from engaging in off-label promotion. The FDA has also requested that companies enter into consent decrees or permanent injunctions under which specified promotional conduct is changed or curtailed. If we cannot successfully manage the promotion of our product candidates, if approved, we could become subject to significant liability, which would materially adversely affect our business and financial condition.
If we are required by the FDA to obtain approval of a companion diagnostic test in connection with approval of any of our product candidates, and we do not obtain or face delays in obtaining FDA approval of a diagnostic device, we will not be able to commercialize such product candidate and our ability to generate revenue will be materially impaired.
If safe and effective use of any of our product candidates depends on an in vitro diagnostic that is not otherwise commercially available, then the FDA generally will require approval or clearance of that diagnostic, known as a companion diagnostic, at the same time that the FDA approves our product candidates if at all. According to FDA guidance, if the FDA determines that a companion diagnostic device is essential to the safe and effective use of a novel therapeutic product or indication, the FDA generally will not approve the therapeutic product or new therapeutic product indication if the companion diagnostic is not also approved or cleared for that indication. If a satisfactory companion diagnostic is not commercially available, we may be required to create or obtain one that would be subject to regulatory approval requirements. The process of obtaining or creating such diagnostic is time consuming and costly.
Companion diagnostics are developed in conjunction with clinical programs for the associated product and are subject to regulation as medical devices by the FDA and comparable regulatory authorities, and, to date, the FDA has generally required premarket approval of all companion diagnostics for cancer therapies. The approval of a companion diagnostic as part of the therapeutic product’s labeling limits the use of the therapeutic product to only those patients who express the specific genetic alteration that the companion diagnostic was developed to detect.
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If the FDA, EMA or a comparable regulatory authority requires approval of a companion diagnostic for any of our product candidates, whether before or after it obtains marketing approval, we, and/or future collaborators, may encounter difficulties in developing and obtaining approval for such product candidate. Any delay or failure by us or third-party collaborators to develop or obtain regulatory approval of a companion diagnostic could delay or prevent approval or continued marketing of such product candidate.
We may also experience delays in developing a sustainable, reproducible and scalable manufacturing process for the companion diagnostic or in transferring that process to commercial partners or negotiating insurance reimbursement plans, all of which may prevent us from completing our clinical trials or commercializing our product candidate, if approved, on a timely or profitable basis, if at all.
Disruptions at the FDA, the SEC and other government agencies caused by funding shortages or global health concerns could hinder their ability to hire and retain key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved or commercialized in a timely manner or at all, or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, which could negatively impact our business.
The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes, and other events that may otherwise affect the FDA’s ability to perform routine functions. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of the Securities and Exchange Commission, or the SEC, and other government agencies on which our operations may rely, including those that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable.
Disruptions at the FDA and other agencies may also slow the time necessary for new drugs to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. For example, in recent years, including in 2018 and 2019, the U.S. government shut down several times and certain regulatory agencies, such as the FDA and the SEC, had to furlough critical employees and stop critical activities. Separately, in response to the COVID-19 pandemic, on March 10, 2020 the FDA announced its intention to postpone most inspections of foreign manufacturing facilities and products, and on March 18, 2020, the FDA temporarily postponed routine surveillance inspections of domestic manufacturing facilities. Subsequently, on July 10, 2020, the FDA announced its intention to resume certain on-site inspections of domestic manufacturing facilities subject to a risk-based prioritization system. The FDA intends to use this risk-based assessment system to identify the categories of regulatory activity that can occur within a given geographic area, ranging from mission critical inspections to resumption of all regulatory activities. Regulatory authorities outside the United States may adopt similar restrictions or other policy measures in response to the COVID-19 pandemic. If a prolonged government shutdown occurs, or if global health concerns continue to prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews, or other regulatory activities, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, in our operations as a public company, future government shutdowns or delays could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.
We may attempt to secure approval from the FDA or comparable foreign regulatory authorities through the use of accelerated approval pathways. If we are unable to obtain such approval, we may be required to conduct additional preclinical studies or clinical trials beyond those that we contemplate, which could increase the expense of obtaining, and delay the receipt of, necessary marketing approvals. Even if we receive accelerated approval from the FDA, if our confirmatory trials do not verify clinical benefit, or if we do not comply with rigorous post-marketing requirements, the FDA may seek to withdraw accelerated approval.
We may in the future seek an accelerated approval for our one or more of our product candidates. Under the accelerated approval program, the FDA may grant accelerated approval to a product candidate designed to treat a serious or life-threatening condition that provides meaningful therapeutic benefit over available therapies upon a determination that the product candidate has an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit. The FDA considers a clinical benefit to be a positive therapeutic effect that is clinically meaningful in the context of a given disease, such as irreversible morbidity or mortality. For the purposes of accelerated approval, a surrogate endpoint is a marker, such as a laboratory measurement, radiographic image, physical sign, or other measure that is thought to predict clinical benefit, but is not itself a measure of clinical benefit. An intermediate clinical endpoint is a clinical endpoint that can be measured earlier than an effect on irreversible morbidity or mortality that is reasonably likely to predict an effect on irreversible morbidity or mortality or other clinical benefit. The accelerated approval pathway may be used in cases in which the advantage of a new drug over available therapy may not be a direct therapeutic advantage, but is a clinically important improvement from a patient
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and public health perspective. If granted, accelerated approval is usually contingent on the sponsor’s agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verity and describe the drug’s clinical benefit. If such post-approval studies fail to confirm the drug’s clinical benefit, the FDA may withdraw its approval of the drug.
Prior to seeking accelerated approval for any of our product candidates, we intend to seek feedback from the FDA and will otherwise evaluate our ability to seek and receive accelerated approval. There can be no assurance that after our evaluation of the feedback and other factors we will decide to pursue or submit an NDA for accelerated approval or any other form of expedited development, review or approval. Similarly, there can be no assurance that after subsequent FDA feedback we will continue to pursue or apply for accelerated approval or any other form of expedited development, review or approval, even if we initially decide to do so. Furthermore, if we decide to submit an application for accelerated approval or receive an expedited regulatory designation (e.g., breakthrough therapy designation) for our product candidates, there can be no assurance that such submission or application will be accepted or that any expedited development, review or approval will be granted on a timely basis, or at all. The FDA or other comparable foreign regulatory authorities could also require us to conduct further studies prior to considering our application or granting approval of any type. A failure to obtain accelerated approval or any other form of expedited development, review or approval for our product candidate would result in a longer time period to commercialization of such product candidate, could increase the cost of development of such product candidate and could harm our competitive position in the marketplace.
We may face difficulties from changes to current regulations and future legislation.
Existing regulatory policies may change and additional government regulations may be enacted that could prevent, limit or delay regulatory approval of our product candidates. We cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if we are not able to maintain regulatory compliance, we may lose any marketing approval that we may have obtained and we may not achieve or sustain profitability.
For example, in March 2010, the Patient Protection and Affordable Care Act of 2010, as amended by the Health Care and Education Reconciliation Act of 2010, or collectively the ACA, was passed, which substantially changes the way healthcare is financed by both the government and private insurers, and significantly impacts the U.S. pharmaceutical industry. Since its enactment, there have been judicial, executive and Congressional challenges to certain aspects of the ACA. By way of example, on December 22, 2017, the Tax Cuts and Jobs Act, or the Tax Act, was signed into law, which included a provision repealing, effective January 1, 2019, the tax-based shared responsibility payment imposed by the ACA on certain individuals who fail to maintain qualifying health coverage for all or part of a year that is commonly referred to as the “individual mandate”. In addition, the 2020 federal spending package permanently eliminates, effective January 1, 2020, the ACA-mandated “Cadillac” tax on high-cost employer-sponsored health coverage and, effective January 1, 2021, also eliminated the health insurer tax. The Bipartisan Budget Act of 2018, or the BBA, among other things, amended the ACA, effective January 1, 2019, to close the coverage gap in most Medicare Part D drug plans. In December 2018, CMS published a new final rule permitting further collections and payments to and from certain ACA-qualified health plans and health insurance issuers under the ACA risk adjustment program in response to the outcome of federal district court litigation regarding the method CMS uses to determine this risk adjustment. On December 14, 2018, a Texas U.S. District Court Judge ruled that the ACA is unconstitutional in its entirety because the “individual mandate” was repealed by Congress as part of the Tax Act. On December 18, 2019, the U.S. Court of Appeals for the 5th Circuit ruled that the individual mandate was unconstitutional and remanded the case back to the District Court to determine whether the remaining provisions of the ACA are invalid as well. The U.S. Supreme Court is currently reviewing the case, although it is unclear when a decision will be made or how the Supreme Court will rule. In addition, there may be other efforts to challenge, repeal or replace the ACA. We are continuing to monitor any changes to the ACA that, in turn, may potentially impact our business in the future.
In addition, other legislative changes have been proposed and adopted in the United States since the ACA was enacted. These changes included aggregate reductions to Medicare payments to providers of 2% per fiscal year, effective April 1, 2013, which, due to subsequent legislative amendments, will stay in effect through 2030, with the exception of a temporary suspension from May 1, 2020 through March 31, 2021 unless additional congressional action is taken. In addition, in January 2013, President Obama signed into law the American Taxpayer Relief Act of 2012, which, among other things, reduced Medicare payments to several providers, and increased the statute of limitations period for the government to recover overpayments to providers from three (3) to five (5) years. These new laws may result in additional reductions in Medicare and other healthcare funding, which could have a material adverse effect on customers for our drugs, if approved, and accordingly, our financial operations.
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Moreover, there has been heightened governmental scrutiny recently over the manner in which drug manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drug products. The likelihood of success of these and other measures proposed by the former administration is unclear, particularly in light of the current administration. At the state level, legislatures have increasingly passed legislation and implemented regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing.
We expect that other healthcare reform measures that may be adopted in the future, may result in more rigorous coverage criteria and in additional downward pressure on the price that we receive for any approved product. Any reduction in reimbursement from Medicare or other government programs may result in a similar reduction in payments from private payors. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability or commercialize our product candidates.
Further, on May 30, 2018, the Trickett Wendler, Frank Mongiello, Jordan McLinn, and Matthew Beilina Right to Try Act of 2017, or the Right to Try Act, was signed into law. The law, among other things, provides a federal framework for certain patients to access certain investigational new product candidates that have completed a Phase 1 clinical trial and that are undergoing investigation for FDA approval. Under certain circumstances, eligible patients can seek treatment without enrolling in clinical trials and without obtaining FDA permission under the FDA expanded access program. There is no obligation for a drug manufacturer to make its products available to eligible patients as a result of the Right to Try Act.
Legislative and regulatory proposals have been made to expand post-approval requirements and restrict sales and promotional activities for biotechnology products. We cannot be sure whether additional legislative changes will be enacted, or whether FDA regulations, guidance or interpretations will be changed, or what the impact of such changes on the marketing approvals of our product candidates, if any, may be. In addition, increased scrutiny by Congress of the FDA’s approval process may significantly delay or prevent marketing approval, as well as subject us to more stringent product labeling and post-marketing testing and other requirements.
Our relationships with healthcare professionals, clinical investigators, CROs and third party payors in connection with our current and future business activities may be subject to federal and state healthcare fraud and abuse laws, false claims laws, transparency laws, government price reporting, and health information privacy and security laws, which could expose us to, among other things, criminal sanctions, civil penalties, contractual damages, exclusion from governmental healthcare programs, reputational harm, administrative burdens and diminished profits and future earnings.
Healthcare providers and third-party payors play a primary role in the recommendation and prescription of any product candidates for which we obtain marketing approval. Our current and future arrangements with healthcare professionals, clinical investigators, CROs, third-party payors and customers may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations that may constrain the business or financial arrangements and relationships through which we market, sell and distribute our products for which we obtain marketing approval. Restrictions under applicable federal and state healthcare laws and regulations include the following:
 
the federal Anti-Kickback Statute prohibits, among other things, persons and entities from knowingly and willfully soliciting, offering, receiving or providing remuneration, directly or indirectly, in cash or in kind, to induce or reward, or in return for, either the referral of an individual for, or the purchase, order or recommendation of, any good or service, for which payment may be made under a federal healthcare program such as Medicare and Medicaid. A person or entity does not need to have actual knowledge of the federal Anti-Kickback Statute or specific intent to violate it in order to have committed a violation;
the federal false claims and civil monetary penalties laws, including the civil False Claims Act, which can be enforced by private citizens through civil whistleblower or qui tam actions, prohibit individuals or entities from, among other things, knowingly presenting, or causing to be presented, to the federal government, claims for payment that are false or fraudulent or making a false statement to avoid, decrease or conceal an obligation to pay money to the federal government. In addition, the government may assert that a claim including items or services resulting from a violation of the U.S. federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the civil False Claims Act;
the federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, prohibits, among other things, executing or attempting to execute a scheme to defraud any healthcare benefit program or making false statements
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relating to healthcare matters. Similar to the federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation;
HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act and their implementing regulations, also imposes obligations, including mandatory contractual terms, with respect to safeguarding the privacy, security and transmission of individually identifiable health information;
the federal Physician Payments Sunshine Act requires applicable manufacturers of covered drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program, with specific exceptions, to annually report to CMS information regarding payments and other transfers of value to physicians, as defined by such law, certain other healthcare providers starting in 2022 and teaching hospitals, as well as information regarding ownership and investment interests held by physicians and their immediate family members. The information reported is publicly available on a searchable website, with disclosure required annually; and
analogous state and foreign laws and regulations, such as state anti-kickback and false claims laws, may apply to sales or marketing arrangements and claims involving healthcare items or services reimbursed by non-governmental third-party payors, including private insurers.
Some state laws require biotechnology companies to comply with the biotechnology industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government and may require drug manufacturers to report information related to payments and other transfers of value to physicians and other healthcare providers or marketing expenditures. Some state laws require biotechnology companies to report information on the pricing of certain drug products.
State and foreign laws also govern the privacy and security of health information in some circumstances, many of which differ from each other in significant ways and often are not preempted by HIPAA, thus complicating compliance efforts. For instance, the collection and use of health data in the European Union is governed by the General Data Protection Regulation, or the GDPR, which extends the geographical scope of European Union data protection law to non-European Union entities under certain conditions, tightens existing European Union data protection principles, creates new obligations for companies and new rights for individuals. Failure to comply with the GDPR may result in substantial fines and other administrative penalties. The GDPR may increase our responsibility and liability in relation to personal data that we process and we may be required to put in place additional mechanisms ensuring compliance with the GDPR. This may be onerous and if our efforts to comply with GDPR or other applicable European Union laws and regulations are not successful, it could adversely affect our business in the European Union. Moreover, the United Kingdom leaving the EU could also lead to further legislative and regulatory changes. It remains unclear how the United Kingdom data protection laws or regulations will develop in the medium to longer term and how data transfer to the United Kingdom from the EU will be regulated, especially following the United Kingdom’s departure from the EU on January 31, 2020 without a deal. However, the United Kingdom has transposed the GDPR into domestic law with the Data Protection Act 2018, which remains in force following the United Kingdom’s departure from the EU. In addition, on June 28, 2018, the State of California enacted the California Consumer Privacy Act, or CCPA, which went into effect on January 1, 2020. The CCPA creates individual privacy rights for California consumers and increases the privacy and security obligations of entities handling certain personal information. The CCPA provides for civil penalties for violations, as well as a private right of action for data breaches that is expected to increase data breach litigation. The CCPA may increase our compliance costs and potential liability, and similar laws have been proposed at the federal level and in other states.
Efforts to ensure that our current and future business arrangements with third parties will comply with applicable healthcare laws and regulations will involve on-going substantial costs. It is possible that governmental authorities will conclude that our business practices may not comply with current or future statutes, regulations or case law involving applicable fraud and abuse or other healthcare laws and regulations. If our operations are found to be in violation of any of these laws or any other governmental regulations that may apply to us, we may be subject to significant penalties, including civil, criminal and administrative penalties, damages, fines, disgorgement, individual imprisonment, exclusion from participation in government funded healthcare programs, such as Medicare and Medicaid, integrity oversight and reporting obligations, contractual damages, reputational harm, diminished profits and future earnings and the curtailment or restructuring of our operations. Defending against any such actions can be costly, time-consuming and may require significant financial and personnel resources. Therefore, even if we are successful in defending against any such actions that may be brought against us, our business may be impaired. Further, if any of the physicians or other healthcare providers or entities with whom we expect to do business is found to be not in compliance with applicable laws, they may be subject to criminal, civil or administrative sanctions, including exclusions from government funded healthcare programs.
Our employees, independent contractors, consultants, commercial collaborators, principal investigators, CROs, suppliers and vendors may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements.
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We are exposed to the risk that our employees, independent contractors, consultants, commercial collaborators, principal investigators, CROs, suppliers and vendors may engage in misconduct or other improper activities. Misconduct by these parties could include failures to comply with FDA regulations, provide accurate information to the FDA, comply with federal and state health care fraud and abuse laws and regulations, accurately report financial information or data or disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the health care industry are subject to extensive laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Misconduct by these parties could also involve the improper use of information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to our reputation. It is not always possible to identify and deter misconduct by these parties, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of significant penalties, including civil, criminal and administrative penalties, damages, fines, disgorgement, individual imprisonment, exclusion from participation in government funded healthcare programs, such as Medicare and Medicaid, integrity oversight and reporting obligations, contractual damages, reputational harm, diminished profits and future earnings and the curtailment or restructuring of our operations.
If we fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on our business.
We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. Our operations involve the use of hazardous and flammable materials, including chemicals and biological materials. Our operations also produce hazardous waste products. We generally contract with third parties for the disposal of these materials and wastes. We cannot eliminate the risk of contamination or injury from these materials. In the event of contamination or injury resulting from our use of hazardous materials, we could be held liable for any resulting damages, and any liability could exceed our resources. We also could incur significant costs associated with civil or criminal fines and penalties.
Although we maintain workers’ compensation insurance to cover us for costs and expenses we may incur due to injuries to our employees resulting from the use of hazardous materials, this insurance may not provide adequate coverage against potential liabilities. We do not maintain insurance for environmental liability or toxic tort claims that may be asserted against us in connection with our storage or disposal of hazardous and flammable materials, including chemicals and biological materials.
In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or commercialization efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions.
Our research and development activities could be affected or delayed as a result of possible restrictions on animal testing.
Certain laws and regulations require us to test our product candidates on animals before initiating clinical trials involving humans. Animal testing activities have been the subject of controversy and adverse publicity. Animal rights groups and other organizations and individuals have attempted to stop animal testing activities by pressing for legislation and regulation in these areas and by disrupting these activities through protests and other means. To the extent the activities of these groups are successful, our research and development activities may be interrupted, delayed or become more expensive.
Our business activities may be subject to the U.S. Foreign Corrupt Practices Act, or the FCPA, and similar anti-bribery and anti-corruption laws of other countries in which we operate, as well as U.S. and certain foreign export controls, trade sanctions, and import laws and regulations. Compliance with these legal requirements could limit our ability to compete in foreign markets and subject us to liability if we violate them.
If we further expand our operations outside of the United States, we must dedicate additional resources to comply with numerous laws and regulations in each jurisdiction in which we plan to operate. Our business activities may be subject to the FCPA and similar anti-bribery or anti-corruption laws, regulations or rules of other countries in which we operate. The FCPA generally prohibits companies and their employees and third party intermediaries from offering, promising, giving or authorizing the provision of anything of value, either directly or indirectly, to a non-U.S. government official in order to influence official action or otherwise obtain or retain business. The FCPA also requires public companies to make and keep books and records that accurately and fairly reflect the transactions of the corporation and to devise and maintain an adequate
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system of internal accounting controls. Our business is heavily regulated and therefore involves significant interaction with public officials, including officials of non-U.S. governments. Additionally, in many other countries, hospitals owned and operated by the government, and doctors and other hospital employees would be considered foreign officials under the FCPA. Recently the SEC and Department of Justice have increased their FCPA enforcement activities with respect to biotechnology and pharmaceutical companies. There is no certainty that all of our employees, agents or contractors, or those of our affiliates, will comply with all applicable laws and regulations, particularly given the high level of complexity of these laws. Violations of these laws and regulations could result in fines, criminal sanctions against us, our officers or our employees, disgorgement, and other sanctions and remedial measures, and prohibitions on the conduct of our business. Any such violations could include prohibitions on our ability to offer our products in one or more countries and could materially damage our reputation, our brand, our international activities, our ability to attract and retain employees and our business, prospects, operating results and financial condition.
In addition, our products and activities may be subject to U.S. and foreign export controls, trade sanctions and import laws and regulations. Governmental regulation of the import or export of our products, or our failure to obtain any required import or export authorization for our products, when applicable, could harm our international sales and adversely affect our revenue. Compliance with applicable regulatory requirements regarding the export of our products may create delays in the introduction of our products in international markets or, in some cases, prevent the export of our products to some countries altogether. Furthermore, U.S. export control laws and economic sanctions prohibit the shipment of certain products and services to countries, governments, and persons targeted by U.S. sanctions. If we fail to comply with export and import regulations and such economic sanctions, penalties could be imposed, including fines and/or denial of certain export privileges. Moreover, any new export or import restrictions, new legislation or shifting approaches in the enforcement or scope of existing regulations, or in the countries, persons, or products targeted by such regulations, could result in decreased use of our products by, or in our decreased ability to export our products to existing or potential customers with international operations. Any decreased use of our products or limitation on our ability to export or sell access to our products would likely adversely affect our business.
Risks Related to Employee Matters, Managing Our Growth and Other Risks Related to Our Business
The COVID-19 pandemic has adversely impacted and we expect will continue to adversely impact our business, including our preclinical studies and clinical trials.
In 2020, a strain of novel coronavirus disease, COVID-19, was declared a pandemic and spread across the world, including throughout the United States, Europe and Asia. The pandemic and government measures taken in response have also had a significant impact, both direct and indirect, on businesses and commerce, as worker shortages have occurred; supply chains have been disrupted; facilities and production have been suspended; and demand for certain goods and services, such as medical services and supplies, has spiked, while demand for other goods and services, such as travel, has fallen. In response to the spread of COVID-19, we have closed our executive offices with our administrative employees continuing their work outside of our offices and limited the number of staff in any given research and development laboratory. As a result of the COVID-19 pandemic, we have experienced and we expect to continue to experience disruptions that could severely impact our business, preclinical studies and clinical trials, including:
 
continued delays or difficulties in enrolling patients in our clinical trials;
continued delays or difficulties in clinical site initiation, including difficulties in recruiting clinical site investigators and clinical site staff;
delays in receiving authorizations from regulatory authorities to initiate our planned clinical trials;
diversion of healthcare resources away from the conduct of clinical trials, including the diversion of hospitals serving as our clinical trial sites and hospital staff supporting the conduct of our clinical trials;
interruption of key clinical trial activities, such as clinical trial site data monitoring, due to limitations on travel imposed or recommended by federal or state governments, employers and others or interruption of clinical trial subject visits and study procedures (such as endoscopies that are deemed non-essential), which may impact the integrity of subject data and clinical study endpoints;
risk that participants enrolled in our clinical trials will contract COVID-19 while the clinical trial is ongoing, which could impact the results of the clinical trial, including by increasing the number of observed adverse events;
risk that we are unable to enroll participants in our clinical trials in adequate numbers;
interruption or delays in the operations of the FDA or other regulatory authorities, which may impact review and approval timelines;
interruption of, or delays in receiving, supplies of our product candidates from our contract manufacturing organizations due to staffing shortages, production slowdowns or stoppages and disruptions in delivery systems;
interruptions in preclinical studies due to restricted or limited operations at our laboratory facility;
delays in necessary interactions with local regulators, ethics committees and other important agencies and contractors due to limitations in employee resources or forced furlough of government employees;
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changes in local regulations as part of a response to the COVID-19 pandemic, which may require us to change the ways in which our clinical trials are conducted, which may result in unexpected costs, or to discontinue such clinical trials altogether;
limitations on employee resources that would otherwise be focused on the conduct of our preclinical studies and clinical trials, including because of sickness of employees or their families or the desire of employees to avoid contact with large groups of people;
interruption or delays to our sourced discovery and clinical activities; and
refusal of the FDA to accept data from clinical trials in affected geographies outside the United States.
The COVID-19 pandemic continues to rapidly evolve. The extent to which the pandemic impacts our business, preclinical studies and clinical trials will depend on future developments, which are highly uncertain and cannot be predicted with confidence, such as the duration of the pandemic, travel restrictions and social distancing in the United States and other countries, business closures or business disruptions and the effectiveness of vaccination efforts and other actions taken in the United States and other countries to contain and treat the disease.
Our success is highly dependent on our ability to attract and retain highly skilled executive officers and employees.
To succeed, we must recruit, retain, manage and motivate qualified clinical, scientific, technical and management personnel, and we face significant competition for experienced personnel. We are highly dependent on the principal members of our management and scientific and medical staff. If we do not succeed in attracting and retaining qualified personnel, particularly at the management level, it could adversely affect our ability to execute our business plan and harm our operating results. In particular, the loss of one or more of our executive officers could be detrimental to us if we cannot recruit suitable replacements in a timely manner. The competition for qualified personnel in the biotechnology field is intense and as a result, we may be unable to continue to attract and retain qualified personnel necessary for the future success of our business. We could in the future have difficulty attracting experienced personnel to our company and may be required to expend significant financial resources in our employee recruitment and retention efforts.
Many of the other biotechnology companies that we compete against for qualified personnel have greater financial and other resources, different risk profiles and a longer history in the industry than we do. They also may provide more diverse opportunities and better prospects for career advancement. Some of these characteristics may be more appealing to high-quality candidates than what we have to offer. If we are unable to continue to attract and retain high-quality personnel, the rate and success at which we can discover, develop and commercialize our product candidates will be limited and the potential for successfully growing our business will be harmed.
If we are unable to establish sales or marketing capabilities or enter into agreements with third parties to sell or market our product candidates, we may not be able to successfully sell or market our product candidates that obtain regulatory approval.
We currently do not have and have never had a marketing or sales team. In order to commercialize any product candidates, if approved, we must build marketing, sales, distribution, managerial and other non-technical capabilities or make arrangements with third parties to perform these services for each of the territories in which we may have approval to sell or market our product candidates. We may not be successful in accomplishing these required tasks.
Establishing an internal sales or marketing team with technical expertise and supporting distribution capabilities to commercialize our product candidates will be expensive and time-consuming, and will require significant attention of our executive officers to manage. Any failure or delay in the development of our internal sales, marketing and distribution capabilities could adversely impact the commercialization of any of our product candidates that we obtain approval to market, if we do not have arrangements in place with third parties to provide such services on our behalf. Alternatively, if we choose to collaborate, either globally or on a territory-by-territory basis, with third parties that have direct sales forces and established distribution systems, either to augment our own sales force and distribution systems or in lieu of our own sales force and distribution systems, we will be required to negotiate and enter into arrangements with such third parties relating to the proposed collaboration. If we are unable to enter into such arrangements when needed, on acceptable terms, or at all, we may not be able to successfully commercialize any of our product candidates that receive regulatory approval or any such commercialization may experience delays or limitations. If we are unable to successfully commercialize our approved product candidates, either on our own or through collaborations with one or more third parties, our future product revenue will suffer and we may incur significant additional losses.
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We have never commercialized a product candidate before and may lack the necessary expertise, personnel and resources to successfully commercialize any products on our own or together with suitable collaborators.
We have never commercialized a product candidate, and we currently have no sales force, marketing or distribution capabilities. To achieve commercial success for the product candidates, which we may license to others, we will rely on the assistance and guidance of those collaborators. For product candidates for which we retain commercialization rights, we will have to develop our own sales, marketing and supply organization or outsource these activities to a third party.
Factors that may affect our ability to commercialize our product candidates on our own include recruiting and retaining adequate numbers of effective sales and marketing personnel, obtaining access to or persuading adequate numbers of physicians to prescribe our product candidates and other unforeseen costs associated with creating an independent sales and marketing organization. Developing a sales and marketing organization will be expensive and time-consuming and could delay the launch of our product candidates. We may not be able to build an effective sales and marketing organization. If we are unable to build our own distribution and marketing capabilities or to find suitable partners for the commercialization of our product candidates, we may not generate revenues from them or be able to reach or sustain profitability.
In order to successfully implement our plans and strategies, we will need to grow the size of our organization, and we may experience difficulties in managing this growth.
In order to successfully implement our development and commercialization plans and strategies, and as we transition into operating as a public company, we expect to need additional managerial, operational, sales, marketing, financial and other personnel. Future growth would impose significant added responsibilities on members of management, including:
 
identifying, recruiting, integrating, maintaining and motivating additional employees;
managing our internal development efforts effectively, including the clinical, FDA, EMA and other comparable foreign regulatory agencies’ review process for ZN-c5, ZN-c3, ZN-d5 and ZN-e4 and any other future product candidates, while complying with any contractual obligations to contractors and other third parties we may have; and
improving our operational, financial and management controls, reporting systems and procedures.
Our future financial performance and our ability to successfully develop and, if approved, commercialize, ZN-c5, ZN-c3, ZN-d5 and ZN-e4 and any other future product candidates will depend, in part, on our ability to effectively manage any future growth, and our management may also have to divert a disproportionate amount of its attention away from day-to-day activities in order to devote a substantial amount of time to managing these growth activities. Furthermore, certain of our employees, including members of our management team, perform services on behalf of Kalyra Pharmaceuticals, Inc., a corporation that is 25% owned by us, pursuant to intercompany service agreements. As a result, such individuals do not allocate all of their time and resources to us and our other subsidiaries which, coupled with the need to manage growth activities, could further limit their ability to devote a sufficient amount of attention to day-to-day activities of our business.
We currently rely, and for the foreseeable future will continue to rely, in substantial part on certain independent organizations, advisors and consultants to provide certain services, including key aspects of clinical development and manufacturing. We cannot assure you that the services of independent organizations, advisors and consultants will continue to be available to us on a timely basis when needed, or that we can find qualified replacements. In addition, if we are unable to effectively manage our outsourced activities or if the quality or accuracy of the services provided by third party service providers is compromised for any reason, our clinical trials may be extended, delayed or terminated, and we may not be able to obtain marketing approval of ZN-c5, ZN-c3, ZN-d5 and ZN-e4 and any other future product candidates or otherwise advance our business. We cannot assure you that we will be able to manage our existing third party service providers or find other competent outside contractors and consultants on economically reasonable terms, or at all.
If we are not able to effectively expand our organization by hiring new employees and/or engaging additional third party service providers, we may not be able to successfully implement the tasks necessary to further develop and commercialize ZN-c5, ZN-c3, ZN-d5 and ZN-e4 and any other future product candidates and, accordingly, may not achieve our research, development and commercialization goals.
Our internal computer systems, or those of any of our CROs, manufacturers, other contractors, consultants, collaborators or potential future collaborators, may fail or suffer security or data privacy breaches or other unauthorized or improper access to, use of, or destruction of our proprietary or confidential data, employee data, or personal data, which could result in additional costs, loss of revenue, significant liabilities, harm to our brand and material disruption of our operations.
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Despite the implementation of security measures, our internal computer systems and those of our current and any future CROs and other contractors, consultants, collaborators and third-party service providers, are vulnerable to damage from computer viruses, cybersecurity threats, unauthorized access, natural disasters, terrorism, war and telecommunication and electrical failure. If such an event were to occur and cause interruptions in our operations or result in the unauthorized acquisition of or access to personally identifiable information or individually identifiable health information (violating certain privacy laws such as HIPAA, Health Information Technology for Economic and Clinical Health Act and GDPR), it could result in a material disruption of our drug discovery and development programs and our business operations, whether due to a loss of our trade secrets or other similar disruptions. Some of the federal, state and foreign government requirements include obligations of companies to notify individuals of security breaches involving particular personally identifiable information, which could result from breaches experienced by us or by our vendors, contractors, or organizations with which we have formed strategic relationships. Notifications and follow-up actions related to a security breach could impact our reputation, cause us to incur significant costs, including legal expenses and remediation costs. For example, the loss of clinical trial data from completed or future clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the lost data. We also rely on third parties to manufacture our product candidates, and similar events relating to their computer systems could also have a material adverse effect on our business. To the extent that any disruption or security breach were to result in a loss of, or damage to, our data, or inappropriate disclosure of confidential or proprietary information, we could be exposed to litigation and governmental investigations, the further development and commercialization of our product candidates could be delayed, and we could be subject to significant fines or penalties for any noncompliance with certain state, federal and/or international privacy and security laws.
Our insurance policies may not be adequate to compensate us for the potential losses arising from any such disruption, failure or security breach. In addition, such insurance may not be available to us in the future on economically reasonable terms, or at all. Further, our insurance may not cover all claims made against us and could have high deductibles in any event, and defending a suit, regardless of its merit, could be costly and divert management attention.
EU drug marketing and reimbursement regulations may materially affect our ability to market and receive coverage for our products in the European member states.
We intend to seek approval to market our product candidates in both the United States and in selected foreign jurisdictions. If we obtain approval in one or more foreign jurisdictions for our product candidates, we will be subject to rules and regulations in those jurisdictions. In some foreign countries, particularly those in the European Union, the pricing of drugs is subject to governmental control and other market regulations which could put pressure on the pricing and usage of our product candidates. In these countries, pricing negotiations with governmental authorities can take considerable time after obtaining marketing approval of a product candidate. In addition, market acceptance and sales of our product candidates will depend significantly on the availability of adequate coverage and reimbursement from third-party payors for our product candidates and may be affected by existing and future healthcare reform measures.
Much like the federal Anti-Kickback Statute prohibition in the United States, the provision of benefits or advantages to physicians to induce or encourage the prescription, recommendation, endorsement, purchase, supply, order or use of medicinal products is also prohibited in the European Union. The provision of benefits or advantages to physicians is governed by the national anti-bribery laws of EU Member States, such as the UK Bribery Act 2010. Infringement of these laws could result in substantial fines and imprisonment.
Payments made to physicians in certain EU Member States must be publicly disclosed. Moreover, agreements with physicians often must be the subject of prior notification and approval by the physician’s employer, his or her competent professional organization and/or the regulatory authorities of the individual EU Member States. These requirements are provided in the national laws, industry codes or professional codes of conduct, applicable in the EU Member States. Failure to comply with these requirements could result in reputational risk, public reprimands, administrative penalties, fines or imprisonment.
In addition, in most foreign countries, including the European Economic Area, or EEA, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing and reimbursement vary widely from country to country. For example, the European Union provides options for its member states to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. Reference pricing used by various EU member states and parallel distribution, or arbitrage between low-priced and high-priced member states, can further reduce prices. A member state may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. In some countries, we may be required to conduct a clinical study or other studies that compare the cost-effectiveness of any of our product candidates to other available therapies in order to obtain or maintain
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reimbursement or pricing approval. There can be no assurance that any country that has price controls or reimbursement limitations for biopharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our products. Historically, products launched in the European Union do not follow price structures of the United States and generally prices tend to be significantly lower. Publication of discounts by third-party payors or authorities may lead to further pressure on the prices or reimbursement levels within the country of publication and other countries. If pricing is set at unsatisfactory levels or if reimbursement of our products is unavailable or limited in scope or amount, our revenues from sales and the potential profitability of any of our product candidates in those countries would be negatively affected.
A portion of our manufacturing of our lead product candidates takes place in China through third-party manufacturers. A significant disruption in the operation of those manufacturers, a trade war or political unrest in China could materially adversely affect our business, financial condition and results of operations.
We currently contract manufacturing operations to third parties, and clinical quantities of our lead product candidates are manufactured by these third parties outside the United States, including in China, and we expect to continue to use such third-party manufacturers for such product candidates. Any disruption in production or inability of our manufacturers in China to produce adequate quantities to meet our needs, whether as a result of a natural disaster or other causes, could impair our ability to operate our business on a day-to-day basis and to continue our development of our product candidates. Furthermore, since these manufacturers are located in China, we are exposed to the possibility of product supply disruption and increased costs in the event of changes in the policies of the United States or Chinese governments, political unrest or unstable economic conditions in China. For example, a trade war could lead to tariffs on the chemical intermediates we use that are manufactured in China. Any of these matters could materially and adversely affect our business and results of operations. Any recall of the manufacturing lots or similar action regarding our product candidates used in clinical trials could delay the trials or detract from the integrity of the trial data and its potential use in future regulatory filings. In addition, manufacturing interruptions or failure to comply with regulatory requirements by any of these manufacturers could significantly delay clinical development of potential products and reduce third-party or clinical researcher interest and support of proposed trials. These interruptions or failures could also impede commercialization of our product candidates and impair our competitive position. Further, we may be exposed to fluctuations in the value of the local currency in China. Future appreciation of the local currency could increase our costs. In addition, our labor costs could continue to rise as wage rates increase due to increased demand for skilled laborers and the availability of skilled labor declines in China.
Our operations are vulnerable to interruption by fire, severe weather conditions, power loss, telecommunications failure, terrorist activity and other events beyond our control, which could harm our business.
Our facility is located in a region which experiences severe weather from time to time. We have not undertaken a systematic analysis of the potential consequences to our business and financial results from a major tornado, flood, fire, earthquake, power loss, terrorist activity or other disasters and do not have a recovery plan for such disasters. In addition, we do not carry sufficient insurance to compensate us for actual losses from interruption of our business that may occur, and any losses or damages incurred by us could harm our business. The occurrence of any of these business disruptions could seriously harm our operations and financial condition and increase our costs and expenses.
Our ability to utilize our net operating loss carryforwards and certain other tax attributes of our corporate subsidiaries may be limited.
The net operating loss, or NOL, carryforwards of the Company and our corporate subsidiaries could expire unused and be unavailable to offset future income tax liabilities because of their limited duration or because of restrictions under U.S. tax law. NOLs generated in tax years ending on or prior to December 31, 2017 are only permitted to be carried forward for 20 taxable years under applicable U.S. federal tax law. Under the Tax Act, as modified by the Coronavirus Aid, Relief, and Economic Security Act, or the CARES Act, signed into law on March 27, 2020, NOLs arising in tax years beginning after December 31, 2017, and before January 1, 2021 may be carried back to each of the five (5) tax years preceding the tax year of such loss, and NOLs arising in tax years beginning after December 31, 2020 may not be carried back. Moreover, under the Tax Act as modified by the CARES Act, federal NOLs of the Company and our corporate subsidiaries generated in tax years ending after December 31, 2017 may be carried forward indefinitely, but the deductibility of federal NOLs generated in tax years beginning after December 31, 2020 may be limited. It is uncertain if and to what extent various states will conform to the Tax Act or the CARES Act. In addition, a “Separate Return Limitation Year” (“SRLY”) generally encompasses all separate return years of a member (or predecessor in a transaction pursuant to Section 381 of the Internal Revenue Code of 1986, as amended, or the Code, or certain other transactions) of a consolidated group, including tax years in which it joins a consolidated return of another group. According to Treasury Regulation Section 1.1502-21, NOLs of a member that arises in a SRLY may be applied against consolidated taxable income only to the extent of the loss member’s cumulative contribution to the consolidated taxable income. As a result, this SRLY limitation may also increase the tax liability of the Company (by reducing the carryforward of
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certain NOLs that otherwise might be used to offset the amount of taxable gain), potentially decreasing the value of our common stock. As of December 31, 2020, our corporate subsidiaries had available NOL carryforwards of approximately $183.0 million for federal income tax purposes, of which $162.0 million were generated in and after 2018 and can be carried forward indefinitely. The remaining federal NOLs of $21.0 million, which were generated prior to 2018, will start to expire in 2033 if not utilized. We do not anticipate carrying back any NOLs of our corporate subsidiaries.
In addition, under Sections 382 and 383 of the Code, if a corporation undergoes an “ownership change” (generally defined as a cumulative change in our ownership by “5-percent shareholders” that exceeds 50 percentage points over a rolling three-year period), the corporation’s ability to use its pre-change NOLs and certain other pre-change tax attributes to offset its post-change income and taxes may be limited. Similar rules may apply under state tax laws. We may have experienced such ownership changes in the past and we may experience ownership changes in the future as a result of shifts in our stock ownership, some of which are outside our control. We have not conducted any studies to determine annual limitations, if any, that could result from such changes in the ownership. Our ability to utilize those NOLs could be limited by an “ownership change” as described above and consequently, we may not be able to utilize a material portion of our NOLs and certain other tax attributes, which could have a material adverse effect on our cash flows and results of operations.
A variety of risks associated with marketing our product candidates internationally could materially adversely affect our business.
We plan to seek regulatory approval of our product candidates outside of the United States and, accordingly, we expect that we will be subject to additional risks related to operating in foreign countries if we obtain the necessary approvals, including:
 
differing regulatory requirements and reimbursement regimes in foreign countries;
unexpected changes in tariffs, trade barriers, price and exchange controls and other regulatory requirements;
economic weakness, including inflation, or political instability in particular foreign economies and markets;
compliance with tax, employment, immigration and labor laws for employees living or traveling abroad;
foreign taxes, including withholding of payroll taxes;
foreign currency fluctuations, which could result in increased operating expenses and reduced revenue, and other obligations incident to doing business in another country;
difficulties staffing and managing foreign operations;
workforce uncertainty in countries where labor unrest is more common than in the United States;
potential liability under the FCPA or comparable foreign regulations;
challenges enforcing our contractual and intellectual property rights, especially in those foreign countries that do not respect and protect intellectual property rights to the same extent as the United States;
production shortages resulting from any events affecting raw material supply or manufacturing capabilities abroad; and
business interruptions resulting from geo-political actions, including war and terrorism.
These and other risks associated with our international operations may materially adversely affect our ability to attain or maintain profitable operations.
Risks Related to Our Intellectual Property
Our success depends on our ability to protect our intellectual property and our proprietary platform.
Our commercial success depends in part on our ability to obtain and maintain patent protection and trade secret protection for our product candidates, proprietary technologies and their uses as well as our and our licensors’ ability to operate without infringing the proprietary rights of others. If we or our licensors are unable to protect our intellectual property rights or if our intellectual property rights are inadequate for our technology or our product candidates, our competitive position could be harmed. We and our licensors generally seek to protect our proprietary position by filing patent applications in the United States and abroad related to our product candidates, proprietary technologies and their uses that are important to our business. Our patent applications cannot be enforced against third parties practicing the technology claimed in such applications unless, and until, patents issue from such applications, and then only to the extent the issued claims cover the technology. There can be no assurance that our patent applications will result in patents being issued or that issued patents will afford sufficient protection against competitors with similar technology, nor can there be any assurance that the patents if issued will not be infringed, designed around, invalidated or rendered unenforceable by third parties. Even issued patents may later be found invalid or unenforceable or may be modified or revoked in proceedings instituted by third parties before various patent offices or in courts. The degree of future protection for our and our licensors’ proprietary rights is uncertain. Only limited protection may be available and may not adequately protect our or our licensors’ rights or permit us or our licensors to gain or keep any
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competitive advantage. These uncertainties and/or limitations in our and our licensors’ ability to properly protect the intellectual property rights relating to our product candidates could have a material adverse effect on our financial condition and results of operations.
Although we license issued patents in the United States and foreign countries, we cannot be certain that the claims in our other U.S. pending patent applications, corresponding international patent applications and patent applications in certain foreign countries will be considered patentable by the United States Patent and Trademark Office, or USPTO, courts in the United States or by the patent offices and courts in foreign countries, nor can we be certain that the claims in our issued patents will not be found invalid or unenforceable if challenged.
The patent application process is subject to numerous risks and uncertainties, and there can be no assurance that we or our licensors or any of our potential future collaborators will be successful in protecting our product candidates by obtaining and defending patents. These risks and uncertainties include the following:
 
the USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other provisions during the patent process, the noncompliance with which can result in abandonment or lapse of a patent or patent application, and partial or complete loss of patent rights in the relevant jurisdiction;
patent applications may not result in any patents being issued;
patents may be challenged, invalidated, modified, revoked, circumvented, found to be unenforceable or otherwise may not provide any competitive advantage;
our competitors, many of whom have substantially greater resources than we or our licensors do and many of whom have made significant investments in competing technologies, may seek or may have already obtained patents that will limit, interfere with or block our ability to make, use and sell our product candidates;
there may be significant pressure on the U.S. government and international governmental bodies to limit the scope of patent protection both inside and outside the United States for disease treatments that prove successful, as a matter of public policy regarding worldwide health concerns; and
countries other than the United States may have patent laws less favorable to patentees than those upheld by U.S. courts, allowing foreign competitors a better opportunity to create, develop and market competing products.
The patent prosecution process is also expensive and time-consuming, and we or our licensors may not be able to file and prosecute all necessary or desirable patent applications at a reasonable cost or in a timely manner or in all jurisdictions where protection may be commercially advantageous. It is also possible that we or our licensors may not identify patentable aspects of our research and development output before it is too late to obtain patent protection. Moreover, in some circumstances, we do not have the right to control the preparation, filing and prosecution of patent applications, or to maintain the patents, directed to technology that we license, including those from our licensors and from third parties. We also may require the cooperation of our licensors in order to enforce the licensed patent rights, and such cooperation may not be provided. Therefore, these patents and applications may not be prosecuted and enforced in a manner consistent with the best interests of our business. We cannot be certain that patent prosecution and maintenance activities by our licensors have been or will be conducted in compliance with applicable laws and regulations, which may affect the validity and enforceability of such patents or any patents that may issue from such applications. If they fail to do so, this could cause us to lose rights in any applicable intellectual property that we in-license, and as a result our ability to develop and commercialize products or product candidates may be adversely affected and we may be unable to prevent competitors from making, using and selling competing products.
In addition, although we enter into non-disclosure and confidentiality agreements with parties who have access to patentable aspects of our research and development output, such as our employees, outside scientific collaborators, CROs, third-party manufacturers, consultants, advisors, licensors, and other third parties, any of these parties may breach such agreements and disclose such output before a patent application is filed, thereby jeopardizing our ability to seek patent protection.
If we fail to comply with our obligations in the agreements under which we license intellectual property rights from our licensors and third parties or otherwise experience disruptions to our business relationships with our licensors, we could lose license rights that are important to our business.
We are a party to a number of license agreements under which we are granted rights to intellectual property that are important to our business and we may enter into additional license agreements in the future. For example, in September 2019, we entered into an exclusive license agreement with Recurium IP Holdings, LLC, or Recurium IP, to obtain an exclusive license to certain intellectual property rights to develop and commercialize ZN-e5, ZN-c3 and ZN-e4.
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This and our other existing license agreements impose on us, and we expect that any future license agreements where we in-license intellectual property will impose on us, various development, regulatory and/or commercial diligence obligations, payment of milestones and/or royalties and other obligations. If we fail to comply with our obligations under these agreements, or we are subject to bankruptcy-related proceedings, the licensors may have the right to terminate the licenses, in which event we would not be able to market products covered by the licenses.
We may need to obtain licenses from third parties to advance our research or allow commercialization of our product candidates, and we cannot provide any assurances that third-party patents do not exist that might be enforced against our product candidates in the absence of such a license. We may fail to obtain any of these licenses on commercially reasonable terms, if at all. Even if we are able to obtain a license, it may be non-exclusive, thereby giving our competitors access to the same technologies licensed to us. In that event, we may be required to expend significant time and resources to develop or license replacement technology. If we are unable to do so, we may