Traws Pharma Inc. 美股招股说明书（2026年5月22日版）

Up to $3,128,399 Common Stock This prospectus supplement amends and supplements the information in the prospectus, dated July11, 2023 (the “Prospectus”), filedwith the Securities and Exchange Commission as a part of our registration statement on FormS-3 (File No.333-273081), aspreviously supplemented by our prospectus supplements, dated March10, 2025 (the “First Supplement”) and April7, 2025 (the“Second Supplement” and together with the First Supplement, the “Prior Supplements”) (the Prior Supplements and the Prospectus arecollectively referred to as the “Prior Prospectus”), relating to the offer and sale from time to time of shares of our common stock, parvalue $0.01 per share, pursuant to that at the market offering agreement (the “ATM Agreement”) we entered into with Citizens JMP To date, we have sold 3,607,270 shares of our common stock for aggregate gross sale proceeds of approximately $7,710,729.46 in We are filing this prospectus supplement to supplement and amend, as of May22, 2026, the Prior Prospectus to update the maximumaggregate gross sales price of shares of our common stock that may be offered, issued and sold under the ATM Agreement.Accordingly, we may offer and sell shares of our common stock having a maximum aggregate gross sales price of up to $3,128,399from time to time to or through Citizens pursuant to the ATM Agreement, which amount is in addition to the gross sale proceeds of Our common stock is listed on the Nasdaq Capital Market under the trading symbol “TRAW.” On May20, 2026, the closing price ofour common stock, as reported on the Nasdaq Capital Market, was $1.62 per share. As of the date of this prospectus supplement, the aggregate market value of our outstanding common stock held by non-affiliates wasapproximately $32,153,972 based on 14,483,771 shares of common stock held by non-affiliates and a price of $2.22 per share, theclosing price of our common stock on March, 23, 2026, which is the highest closing price of our common stock on the Nasdaq CapitalMarket within the prior 60days of this prospectus supplement. During the 12 calendarmonths prior to and including the date of thisprospectus supplement (excluding this offering), we have sold approximately $7,588,520 of securities pursuant to General Instruction We are a “smaller reporting company” as that term is defined under the federal securities laws, and, as such, have elected to rely oncertain reduced public company disclosure requirements. See “Prospectus Supplement Summary — Implications of Being a Smaller Investing in our common stock involves certain risks. See “Risk Factors” beginning on pageS-9of the First Supplement, in theaccompanyingprospectus and in the documents incorporated by reference in this prospectus supplement,the Prior Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any Citizens Capital MarketsMay22, 2026