As filed with the Securities and Exchange Commission on April 2, 2020

Registration No. 333-                    

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Zentalis Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

530 Seventh Avenue, Suite 2201

New York, New York 10018

(212) 433-3791

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Anthony Y. Sun, M.D.

Chief Executive Officer

Zentalis Pharmaceuticals, Inc.

530 Seventh Avenue, Suite 2201

New York, New York 10018

(212) 433-3791

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public:

As soon as practicable after this Registration Statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box.  ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☒ 333-236959

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

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.

If an emerging growth company, indicate by checkmark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided to Section 7(a)(2)(B) of the Securities Act.  ☐

CALCULATION OF REGISTRATION FEE

This Registration Statement shall become effective upon filing with the Securities and Exchange Commission in accordance with Rule 462(b) promulgated under the Securities Act.

EXPLANATORY NOTE AND INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

This Registration Statement is being filed with the Securities and Exchange Commission (the “SEC”), pursuant to Rule 462(b) under the Securities Act of 1933, as amended (the “Securities Act”). This Registration Statement relates to the public offering of common stock, par value $0.001 per share (the “Common Stock”), of Zentalis Pharmaceuticals, Inc. (the “Registrant”), contemplated by the Registration Statement on Form S-1, as amended (File No. 333-236959), initially filed with the SEC by the Registrant on March 6, 2020 (as amended, the “Prior Registration Statement”) pursuant to the Securities Act, which was declared effective by the SEC on April 2, 2020. The contents of the Prior Registration Statement, including all amendments and exhibits thereto, are incorporated by reference into this Registration Statement.

The Registrant is filing this Registration Statement for the sole purpose of increasing the aggregate offering price of shares to be offered in the public offering by $31,671,000, which includes additional shares that the underwriters have the option to purchase. The additional shares of Common Stock that are being registered for issuance and sale are in an amount and at a price that together represent no more than 20% of the maximum aggregate offering price set forth in the Calculation of Registration Fee table contained in the Prior Registration Statement.

The required opinion and consents are listed in Part II, Item 16 of this Registration Statement and filed herewith.

PART II

Information Not Required in Prospectus

The following documents are filed as exhibits to this Registration Statement, and all other exhibits previously filed as exhibits to the Registrant’s Registration Statement on Form S-1, as amended (File No. 333-236959), are incorporated by reference into, and shall be deemed to be a part of, this filing.

SIGNATURES

Pursuant to the requirements of the Securities Act, the registrant has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of New York, State of New York, on this 2nd day of April, 2020.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities held on the dates indicated.

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement on Form S-1 filed pursuant to Rule 462(b) of the Securities Act of 1933 of the reference to our firm under the caption “Experts” and to the incorporation by reference of our report dated March 6, 2020, with respect to the financial statements of Zentalis Pharmaceuticals, LLC included in Amendment No. 1 to the Registration Statement (Form S-1 No. 333-236959) and related Prospectus of Zentalis Pharmaceuticals, LLC for the registration of its common stock.

/s/ Ernst & Young LLP

San Diego, California

April 2, 2020