SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)*

Tango Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.001 par value

(Class of Securities)

87583X109

(CUSIP Number)

Kevin Gillis

Third Rock Ventures, LLC

201 Brookline Ave, Suite 1401, Boston, MA 02215

(617) 585-2000

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 30, 2024

(Date of Event Which Requires Filing of Statement on Schedule 13D)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), checking the following box. ☐

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP: 87583X109

CUSIP: 87583X109

CUSIP: 87583X109

CUSIP: 87583X109

EXPLANATORY STATEMENT

This Amendment No. 1(this “Amendment”) amends and supplements the Schedule 13D (the “Schedule 13D”) filed by the Reporting Persons on August 19, 2021, with respect to the shares of common stock, $0.001 par value per share (“Common Stock”), of Tango Therapeutics, Inc. (the “Company” or the “Issuer”). The transactions described in Item 5(c) resulted in a decrease of over one percent (1%) in the aggregate percentage ownership reported by the Reporting Persons in the Schedule 13D. Except as specifically provided herein, this Amendment does not modify any of the information previously reported in the Schedule 13D.

Item 5(a)-(c) is hereby amended and restated as follows:

(a) As of August 30, 2024, TRV IV had shared voting and dispositive power with respect to 17,001,475 shares of the Issuer’s Common Stock, constituting approximately 15.9% of the Issuer’s outstanding Common Stock.

As of August 30, 2024, Third Rock Ventures GP IV, L.P. (“TRV GP IV”), as the general partner of TRV IV may be deemed to have shared voting and dispositive power with respect to all 17,001,475 shares of the Issuer’s Common Stock owned by TRV IV, constituting approximately 15.9% of the Issuer’s outstanding Common Stock.

As of August 30, 2024, TRV GP IV, LLC (“TRV GP IV LLC,” and collectively with TRV IV and TRV GP IV, the “Reporting Persons”), as the general partner of TRV GP IV may be deemed to have shared voting and dispositive power with respect to all 17,001,475 shares of the Issuer’s Common Stock owned by TRV IV, constituting approximately 15.9% of the Issuer’s outstanding Common Stock.

The percent of class was calculated based on 107,144,465 shares of common stock issued and outstanding as of August 1, 2024, as disclosed in the Issuer’s 10-Q filed with the Securities and Exchange Commission on August 7, 2024.

(b)

Regarding the number of shares as to which such person has:

(i) sole power to vote or to direct the vote: See line 7 of cover sheets

(ii) shared power to vote or to direct the vote: See line 8 of cover sheets

(iii) sole power to dispose or to direct the disposition: See line 9 of cover sheets.

(iv) shared power to dispose or to direct the disposition: See line 10 of cover sheets

(c) Except as set forth in the table below, no transactions in the Common Stock were effected by the Reporting Persons during the 60-day period ended August 30, 2024.

CUSIP: 87583X109

SIGNATURE

After reasonable inquiry and to the best of his knowledge and belief, the undersigned certifies that the information set forth in this Statement is true, complete and correct.

Dated: September 4, 2024