Xilio Therapeutics Inc 美股招股说明书（2026年2月11日版）

Up to $9,500,000Common Stock This prospectus supplement amends and supplements certain information in the prospectus, dated May8, 2025, filed with the Securities andExchange Commission as a part of our registration statement on Form S-3 (File No.333-285703), which we refer to as the Prior Prospectus, relating tothe offer and sale of shares of our common stock, par value $0.0001 per share, having an aggregate offering price of up to $50,000,000 pursuant to theSales Agreement, dated March11, 2025, or the sales agreement, that we previously entered into with Leerink Partners LLC. As of the date of thisprospectus supplement, we have not sold any shares of our common stock in accordance with the sales agreement under the Prior Prospectus. This We are filing this prospectus supplement to amend the Prior Prospectus to reduce the amount of common stock we may offer and sell under thesales agreement such that we are offering up to an aggregate of $9,500,000 of our common stock for sale under the sales agreement from and after the Our common stock is listed on The Nasdaq Capital Market under the trading symbol “XLO.” On February10, 2026, the last sale price of ourcommon stock as reported on The Nasdaq Capital Market was $0.5415 per share. Investing in our common stock involves certain risks. See “Risk Factors” beginning on page SA-7 of the PriorProspectus and in the documents incorporated by reference in the Prior Prospectus for a discussion of the factors you Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passedupon the adequacy or accuracy of the Prior Prospectus or this prospectus supplement. Any representation to the contrary is a criminal offense. Leerink PartnersFebruary11, 2026