Tango Therapeutics, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

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Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

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TANGO THERAPEUTICS, INC.

(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):

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☐ Fee paid previously with preliminary materials.

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

Dear Fellow Stockholder:

Tango Therapeutics was founded with a clear mission: to discover the next generation of targeted therapies in oncology by addressing the specific genetic alterations that drive cancer. We leverage our state-of-the-art target and drug discovery platforms to identify novel disease-relevant targets and develop medicines tailored to defined patient populations with high unmet medical need. Our novel small molecules are designed to be selectively active in cancer cells with specific genetic alterations, killing those cancer cells while sparing normal cells. We believe our approach will provide the ability to deliver deep, durable target inhibition with favorable tolerability and safety profiles, thus potentially maximizing clinical benefit.

We made significant progress across our research and clinical development programs in 2025:

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In October 2025, we reported positive data from the ongoing monotherapy Phase 1/2 clinical trial of vopimetostat, our lead PRMT5 inhibitor, demonstrating durable clinical activity across multiple cancer types, with a strong safety and tolerability profile. We plan to initiate our first pivotal study in second line pancreatic cancer for vopimetostat in 2026.

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In June 2025, we treated the first patient in our Phase 1/2 trial of vopimetostat and Revolution Medicines’ daraxonrasib (RAS(ON) multi-selective inhibitor) or zoldonrasib (RAS(ON) G12D-selective inhibitor) in patients with MTAP-deleted and RAS mutant metastatic pancreatic or lung cancer. We are encouraged by the early efficacy signals and safety profile emerging from this study and plan to provide a safety and efficacy update for this study in 2026, which we believe will inform a path to first line pancreatic cancer.

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In May 2025, we treated the first patient in the Phase 1/2 trial of TNG456 in patients with MTAP-deleted solid tumors, with a focus on glioblastoma. TNG456 is a next-generation, brain-penetrant, MTA-cooperative PRMT5 inhibitor. We plan to share initial safety and efficacy data from this study in 2026.

The board of directors and I are pleased to invite you to attend the 2026 Annual Meeting of Stockholders, or the Annual Meeting, of Tango Therapeutics, Inc., or Tango, or the Company, to be held virtually on Thursday, June 4, 2026 at 9:00 a.m. Eastern Time. Stockholders will have the ability to participate in the Annual Meeting, vote their shares and ask questions by accessing the virtual meeting.

At the Annual Meeting, our stockholders will be asked to: (1) elect three nominees who are named in the Proxy Statement as Class II Directors; (2) ratify the appointment of PricewaterhouseCoopers LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2026; (3) hold a non-binding, advisory vote to approve the compensation of our named executive officers; and (4) transact any other business that properly comes before the Annual Meeting (including adjournments, continuations and postponements thereof). Our board of directors recommends that you vote “FOR” the election of the director nominees, “FOR” the ratification of the appointment of PricewaterhouseCoopers LLP, and “FOR” the approval, on a non-binding, advisory basis, of the compensation of our named executive officers. You should carefully read our proxy materials, which contain detailed information concerning each of these proposals.

Under the Securities and Exchange Commission rules, the Company is providing access to the proxy materials for the Annual Meeting to stockholders via the Internet. Accordingly, you can access the proxy materials and vote at www.proxyvote.com. Instructions for accessing the proxy materials and voting are described below and in the Notice of Internet Availability of Proxy Materials that you received in the mail (unless you have previously requested a paper copy of our proxy materials). The Notice of Internet Availability of Proxy Materials also contains instructions on how to request a paper copy of our proxy materials and our Annual Report on Form 10-K for the year ended December 31, 2025. This process allows us to provide our stockholders with the information they need on a more timely basis, while reducing the environmental impact and lowering the costs of printing and distributing our proxy materials.

Your vote is very important. Whether or not you plan to virtually attend the meeting, please carefully review the proxy materials and then cast your vote. If you are a stockholder of record and have received our Notice of Internet Availability of Proxy Materials, then instructions regarding how you can vote are contained in that notice. If you requested to receive a printed set of the proxy materials, please vote by completing, signing, dating and mailing the accompanying proxy card in the return envelope or voting by telephone or the Internet, in accordance with the instructions set forth on the proxy card. Submitting your vote via the Internet, by telephone or proxy card will not affect your right to attend and to vote at the Annual Meeting if you decide to virtually attend the Annual Meeting. If your shares are held in street name (held for your account by a broker or other nominee), you will receive instructions from your broker or other nominee explaining how to vote your shares, and you will have the option to cast your vote by telephone or over the Internet if your voting instruction form from your broker or nominee includes instructions and a toll-free telephone number or Internet website to do so. In any event, to be sure that your vote will be received in time, please cast your vote by your choice of available means at your earliest convenience.

On behalf of our board of directors, team members, and patients, thank you for your ongoing support of, and continued interest in, Tango.

Sincerely,

Malte Peters, M.D.

President and Chief Executive Officer

Tango Therapeutics, Inc.

201 Brookline Avenue, Suite 901

Boston, MA 02215

NOTICE OF 2026 ANNUAL MEETING OF STOCKHOLDERS

To be held on June 4, 2026

Notice is hereby given that the 2026 Annual Meeting of Stockholders, or Annual Meeting, of Tango Therapeutics, Inc., will be held online on Thursday, June 4, 2026. You may attend the meeting virtually via the Internet, where you will be able to participate in the meeting, vote electronically and submit questions that are germane to the matters under consideration at the Annual Meeting. You will need the 16-digit control number included with the Notice of Internet Availability of Proxy Materials, your proxy card (if you received a printed copy of the proxy materials) or in the instructions that accompanied your proxy materials in order to attend the Annual Meeting.

The purpose of the Annual Meeting is the following:

1. To elect three Class II Directors (Malte Peters, M.D., Kanishka Pothula, and Mace Rothenberg, M.D.) to our board of directors, each to serve until the 2029 annual meeting of stockholders and until his successor has been duly elected and qualified, or until his earlier death, resignation or removal;

2. To ratify the appointment of PricewaterhouseCoopers LLP as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2026;

3. To approve, on a non-binding, advisory basis, the compensation of our named executive officers; and

4. To transact any other business properly brought before the Annual Meeting or any adjournment or postponement of the Annual Meeting.

The Annual Meeting will begin promptly at 9:00 a.m. Eastern Time. Only stockholders of record at the close of business on April 7, 2026 will be entitled to vote at the Annual Meeting and any adjournment or postponement thereof.

We are pleased to adhere to the Securities and Exchange Commission’s “Notice and Access” rule that allows companies to furnish their proxy materials by posting them on the Internet. As a result, we are mailing to our stockholders a Notice of Internet Availability of Proxy Materials, or the Notice, instead of a paper copy of the accompanying proxy statement and our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, or 2025 Annual Report. We plan to mail the Notice on or about April 17, 2026, and it contains instructions on how to access both the 2025 Annual Report and accompanying proxy statement over the Internet. This method provides our stockholders with expedited access to proxy materials and not only lowers the cost of printing and distribution but also reduces the environmental impact of the Annual Meeting. If you would like to receive a print version of the proxy materials, free of charge, please follow the instructions in this Notice.

To be virtually admitted to the Annual Meeting and vote your shares, you must provide the 16-digit control number as provided in the Notice, your proxy card (if you received a printed copy of the proxy materials) or in the instructions that accompanied your proxy materials. Please see the “General Information Regarding the Meeting” 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 that are germane to the topics under consideration at the Annual Meeting during the Annual Meeting, and technical details and support related to accessing the virtual platform.

Your vote is important. Whether or not you expect to attend the Annual Meeting virtually, 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 meeting, by submitting your proxy via the Internet at the address listed on the proxy card, via the telephone number listed on the proxy card or by signing, dating and returning the proxy card. Even if you have voted by proxy, you may still vote at the Annual Meeting. Please note, however, that if your shares are held through a broker, bank or other nominee and you wish to vote at the Annual Meeting, you must obtain a proxy issued in your name from that record holder.

By order of the Board of Directors,

Julie Fogarty

Vice President, Legal and Corporate Secretary

Boston, MA

April 17, 2026

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