Tango Therapeutics Inc美股招股说明书(2026-06-08版)

The information in this preliminary prospectus supplement is not complete and may be changed. A registration statementrelating to these securities has been filed with the Securities and Exchange Commission and is effective. This preliminaryprospectus supplement and the accompanying prospectus are not an offer to sell these securities and we are not soliciting anoffer to buy these securities in any jurisdiction where the offer or sale is not permitted. Subject to completion, dated June8, 2026 Preliminary prospectus supplement(to Prospectus dated November21, 2025) $500,000,000 Shares of Common Stock We are offering $500,000,000 of shares of our common stock, par value $0.001 per share, or the common stock, pursuant to thisprospectus supplement and the accompanying prospectus. Our common stock is listed on The Nasdaq Global Market, or Nasdaq, under the symbol “TNGX”. The last sale price as reported on TheNasdaq Global Market on June5, 2026, was $20.22 per share. Investing in our common stock involves risks. See “RiskFactors” on page S-8 of this prospectus supplement, and under similarheadings in other documents filed after the date hereof and incorporated by reference into this prospectus supplement and theaccompanying prospectus. Neither the Securities and Exchange Commission, any state securities commission nor any other regulatory body has approvedor disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful orcomplete. Any representation to the contrary is a criminal offense. Proceeds, before expenses, to us (1)We refer you to “Underwriting” beginning on page S-28 of this prospectus supplement for additional information regarding underwriting compensation. The underwriters may also exercise their option to purchase up to an additional $75,000,000 of shares of common stock from us, at thepublic offering price, less the underwriting discount, for 30 days after the date of this prospectus supplement. The underwriters expect to deliver the shares of common stock offered pursuant to this prospectus supplement and accompanyingprospectus on or about, 2026. J.P.Morgan Stifel Cantor Prospectus supplement dated Table of Contents Table of contents Prospectus supplement About this prospectus supplementProspectus supplement summaryThe offeringRisk factorsSpecial note regarding forward-looking statementsUse of proceedsDividend policyDilutionDescription of capital stockCertain material U.S. federal income tax considerationsUnderwritingLegal mattersExpertsWhere you can find more informationIncorporation by reference Prospectus About this prospectusRisk factorsSpecial note regarding forward-looking statementsOur companyUse of proceedsSecurities that may be offered Legal matters Experts Table of Contents About this prospectus supplement This document contains two parts. The first part is this prospectus supplement, which describes the specific terms of this offering of ourcommon stock and also supplements and updates information contained in the accompanying prospectus and the documentsincorporated by reference into this prospectus supplement and the accompanying prospectus. The second part is the accompanyingprospectus included in our automatic shelf registration statement on Form S-3 (File No.333-291684) that we filed with the Securities andExchange Commission, or the SEC, on November21, 2025, as a “well-known seasoned issuer” as defined in Rule 405 of the SecuritiesAct of 1933, as amended, or the Securities Act, along with the documents incorporated by reference, which provides more generalinformation, some of which may not apply to this offering. Generally, when we refer to this prospectus, we are referring to both parts of thisdocument combined. To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the informationcontained in the accompanying prospectus or in any document incorporated by reference that was filed with the SEC before the date ofthis prospectus supplement, on the other hand, you should rely on the information contained in this prospectus supplement. If anystatement in one of these documents is inconsistent with a statement in another document having a later date—for example, a documentincorporated by reference in the accompanying prospectus—the statement in the document having the later date modifies or supersedesthe earlier statement. This prospectus supplement and the accompanying prospectus are part of a “shelf” registration statement that we filed with the SEC.Under the shelf registration process, we may offer from time to time various securities, including our common stock. Such registrationstatement also includes exhibits that provide more detail on the matters discussed in this prospectus supplement and the accompanyingprospectus. You should read this prospectus supplement, the accompanying prospectus, including the information incorporated byref