Whitehawk Therapeutics, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934

Filed by the Registrantx

Filed by a party other than the Registranto

Check the appropriate box:

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

April 28, 2026

To the Stockholders of Whitehawk Therapeutics, Inc.:

You are cordially invited to attend the 2026 Annual Meeting of Stockholders (the "Annual Meeting") of Whitehawk Therapeutics, Inc. (the “Company”), which will be held online on Thursday, June 11, 2026 at 1:00 p.m. Eastern Time via webcast atwww.virtualshareholdermeeting.com/WHWK2026. The Annual Meeting will be a completely virtual meeting which will be conducted via live webcast.

Details regarding admission to the meeting and the business to be conducted are more fully described in the accompanying Notice of Annual Meeting and Proxy Statement.

At this Annual Meeting, the agenda includes:

To elect three Class III directors to serve on the Company’s board of directors until the Company’s 2029 annual meeting of stockholders and until their successors are duly elected and qualified, or until their earlier resignation, death or removal;

To approve, on an advisory basis, the compensation of the named executive officers identified in the 2025 Summary Compensation Table in the “Executive Compensation” section of the proxy statement;

To ratify the appointment of BDO USA, P.C. as the Company’s independent registered accounting firm for the fiscal year ending December 31, 2026; and

To transact such other business as may properly come before the Annual Meeting or any adjournments or postponements thereof.

Whether or not you attend the Annual Meeting, it is important that your shares be represented and voted at the meeting. Therefore, we urge you to promptly vote and submit your proxy via the Internet, by phone or, if you requested printed copies of the proxy materials by mail, by signing, dating and returning the enclosed proxy card in the enclosed envelope. If you decide to attend the Annual Meeting, you will be able to change your vote, revoke your proxy or vote electronically at the Annual Meeting.

We hope that you will join us virtually on June 11, 2026. Your investment and continuing interest in the Company are very much appreciated.

Sincerely yours,

/s/ David Lennon

David Lennon, Ph.D.

President & Chief Executive Officer

/s/ Caley Castelein

Caley Castelein, M.D.

Chairman of the Board

2 Headquarters Plaza, East Building, 11th Floor

Morristown, New Jersey 07960

NOTICE OF 2026 ANNUAL MEETING OF STOCKHOLDERS

To Be Held Online on Thursday, June 11, 2026 at

www.virtualshareholdermeeting.com/WHWK2026

Notice is hereby given that the 2026 Annual Meeting of Stockholders (the “Annual Meeting”) of Whitehawk Therapeutics, Inc. (the “Company”), will be held online on June 11, 2026 at 1:00 p.m. Eastern Time. The Annual Meeting will be a virtual meeting, which will be conducted via live webcast. You will be able to attend the meeting virtually via the Internet, vote your shares electronically and submit your questions during the Annual Meeting via the Internet atwww.virtualshareholdermeeting.com/WHWK2026. You will need your 16-digit control number, which is located on the Notice of Internet Availability of Proxy Materials (the “Notice of Availability”) that you received in the mail, on your proxy card or in the instructions accompanying your proxy materials, to attend the Annual Meeting.

The purpose of the Annual Meeting is the following:

To elect three Class III directors to serve on the Company’s board of directors until the Company’s 2029 annual meeting of stockholders and until their successors are duly elected and qualified, or until their earlier resignation, death or removal;

To approve, on an advisory basis, the compensation of the named executive officers identified in the 2025 Summary Compensation Table in the “Executive Compensation” section of the proxy statement;

To ratify the appointment of BDO USA, P.C. as the Company’s independent registered accounting firm for the fiscal year ending December 31, 2026; and

To transact such other business as may properly come before the Annual Meeting or any adjournments or postponements thereof.

Stockholders of record at the close of business on April 17, 2026, the record date for the Annual Meeting (the “Record Date”), are entitled to notice of, and to vote at, the Annual Meeting or any adjournment or postponement of the Annual Meeting. Further information regarding voting rights and matters to be voted upon is presented in the accompanying proxy statement.

To participate in the Annual Meeting, you will be required to enter the 16-digit control number provided in the Notice of Availability or the proxy card atwww.virtualshareholdermeeting.com/WHWK2026 and beneficial owners of shares held in street name must additionally follow the instructions provided by the broker, bank or other nominee that holds their shares. Please see the “General Information” section of the Proxy Statement that accompanies this notice for more details regarding the logistics of the virtual Annual Meeting, including the ability of stockholders to submit questions during the Annual Meeting, and technical details and support related to accessing the virtual platform. You will not be able to attend the Annual Meeting in person.

YOUR VOTE IS IMPORTANT. Whether or not you are able to attend the Annual Meeting, it is important that your shares be represented. To ensure that your vote is recorded promptly, please vote as soon as possible, even if you plan to attend the Annual Meeting, by submitting your proxy over the Internet or by telephone as described in the instructions included in the Notice of Availability or by signing, dating and returning the proxy card. Returning the proxy does not deprive you of your right to attend the Annual Meeting and to vote your shares at the Annual Meeting.

Important Notice Regarding the Availability of Proxy Material for the Annual Meeting to be held on June 11, 2026. Our proxy statement and Annual Report to the Stockholders are being made available on or about April 28, 2026 atwww.proxyvote.com. We are providing access to our proxy materials over the Internet under the “notice and access” rules adopted by the Securities and Exchange Commission.

By order of the Board of Directors,

/s/ David Lennon

David Lennon, Ph.D.

President & Chief Executive Officer

TABLE OF CONTENTS

2 Headquarters Plaza, East Building, 11th Floor

Morristown, New Jersey 07960

PROXY STATEMENT

FOR THE 2026 ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ONLINE ON THURSDAY, JUNE 11, 2026

This proxy statement (“Proxy Statement”) is furnished in connection with the solicitation of proxies by the Board of Directors (the “Board”) of Whitehawk Therapeutics, Inc. (the “Company”) for use at the 2026 Annual Meeting of Stockholders of the Company and at any adjournments, postponements or continuations thereof (the “Annual Meeting”). The Annual Meeting will be held at 1:00 p.m. Eastern Time on Thursday, June 11, 2026. The Annual Meeting will be a virtual meeting, which will be conducted via live webcast.

There will be no physical location for stockholders to attend. You will be able to attend the meeting virtually via the Internet atwww.virtualshareholdermeeting.com/WHWK2026, where you will be able to vote electronically and submit questions. To participate in the Annual Meeting, you will need your 16-digit control number, which is located on the Notice of Internet Availability of Proxy Materials (the “Notice of Availability”) that you received in the mail, included on your proxy card (printed in the box and marked by the arrow) or on the instructions that accompanied your proxy materials. The Notice of Availability containing instructions on how to access the Proxy Statement and our Annual Report is first being mailed on or about April 28, 2026 to all stockholders entitled to vote at the Annual Meeting. The Proxy Statement and our 2025 Annual Report can be accessed by following the instructions in the Notice of Availability.

Please see the “General Information” section of the Proxy Statement for more details regarding the logistics of the virtual Annual Meeting, including the ability of stockholders to submit questions during the Annual Meeting, and technical details and support related to accessing the virtual platform. You will not be able to attend the Annual Meeting in person.

All properly submitted proxies will be voted in accordance with the instructions contained in those proxies. If no instructions are specified, the proxies will be voted in accordance with the recommendation of our Board with respect to each of the matters set forth in the accompanying Notice of Meeting. You may revoke your proxy at any time before it is exercised at the meeting by giving our corporate secretary written notice to that effect.

In this Proxy Statement, the terms “Whitehawk,” the “company,” “we,” “us,” and “our” refer to Whitehawk Therapeutics, Inc. The mailing address of our principal executive offices is Whitehawk Therapeutics, Inc., 2 Headquarters Plaza, East Building, 11th Floor, Morristown, New Jersey 07960.

Important Notice Regarding the Availability of Proxy Materials for

the Annual Meeting of Stockholders to be Held on June 11, 2026

This Proxy Statement and our Annual Report are

available for viewing, printing and downloading atwww.proxyvote.com

A copy of our 2025 Annual Report will be furnished without charge to any stockholder upon written request to Whitehawk Therapeutics, Inc., 2 Headquarters Plaza, East Building, 11th Floor, Morristown, New Jersey 07960, Attention: Corporate Secretary. This Proxy Statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 are also available on the Securities and Exchange Commission ("SEC") website atwww.sec.gov.

PROXY STATEMENT

FOR THE 2026 ANNUAL MEETING OF STOCKHOLDERS