Item 1.01 Entry into a Material Definitive Agreement.

Item 3.02 Unregistered Sales of Equity Securities. To the extent required by Item 3.02 of Form8-K, the information regarding the Private Placement set forth under Item 1.01 of this Current Report on Form8-Kis incorporated by reference in this Item 3.02. The PIPE Shares issued and sold in the Private Placement are being offered pursuant to Section 4(a)(2) of the Securities Act, and Rule 506(b) of Regulation D as promulgated by the SEC under the Securities Act. The Company relied on this exemption from registration for the Private Placement based in part on the representations made by the Purchaser, including the representations with respect to the Purchaser’s investment intent. The securities were not issued through any general solicitation or advertisement. A Form D filing will be made following the closing of the Private Placement in accordance with the requirements of Regulation D. Neither this Current Report on Form8-Knor any exhibit attached hereto is an offer to sell or the solicitation of an offer to buy shares of Common Stock or other securities of the Company.

Item 9.01 Exhibits 1.1 Underwriting Agreement, dated October 23, 2025, between Tango Therapeutics, Inc. and Leerink Partners LLC. ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 4.1 Form of Pre-Funded Warrant 5.1 Opinion of Goodwin Procter LLP. 10.1 Securities Purchase Agreement, dated as of October 23, 2025, by and between Tango Therapeutics, Inc. and the Purchaser. 23.1 Consent of Goodwin Procter LLP (contained in Exhibit 5.1) 104 Cover Page Interactive Data File (embedded within Inline XBRL document). SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. TANGO THERAPEUTICS, INC. Date: October 24, 2025 By: /s/ Daniella Beckman Name: Daniella Beckman Title: Chief Financial Officer