Xilio Therapeutics, Inc.(Exact name of registrant as specified in its charter) 85-1623397(I.R.S. EmployerIdentification Number) Securities registered pursuant to Section 12(b) of the Act: Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of theSecurities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to filesuch reports), and (2) has been subject to such filing requirements for the past 90 days. Yes☒No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to besubmitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorterperiod that the registrant was required to submit such files). Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, asmaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,”“smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act. If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition periodfor complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes☐No☒ Number of shares of the registrant's common stock, $0.0001 par value per share, outstanding on May 8, 2026: 5,982,839 References to Xilio Unless otherwise stated, all references to “us,” “our,” “we,” “Xilio,” “Xilio Therapeutics,” “the Company” and similarreferences in this Quarterly Report on Form 10-Q refer to Xilio Therapeutics, Inc. and its consolidated subsidiaries. XilioTherapeutics and its associated logos are registered trademarks of Xilio Therapeutics, Inc. Other brands, names and trademarkscontained in this Quarterly Report on Form 10-Q are the property of their respective owners. Cautionary Note Regarding Forward-Looking Statements This Quarterly Report on Form 10-Q contains forward-looking statements within the meaning of the U.S. Private SecuritiesLitigation Reform Act of 1995 that involve substantial risks and uncertainties. All statements, other than statements of historicalfacts, contained in this Quarterly Report on Form 10-Q are forward-looking statements. In some cases, you can identify forward-looking statements by words such as “aim,” “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,”“intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “would,” or the negative of these words orother comparable terminology, although not all forward-looking statements contain these identifying words. The forward-looking statements in this Quarterly Report on Form 10-Q include, but are not limited to, statements about: •the initiation, timing, progress and results of our research and development programs, including preclinical studies andclinical trials;•our estimates regarding expenses, future revenue and capital requirements and our expectations regarding our ability tofund our operating expenses and capital expenditure requirements with our cash and cash equivalents;•our ability to establish and maintain collaborations and strategic partnerships and realize the expected benefits of sucharrangements, including our collaboration agreement with AbbVie Group Holdings Limited, or AbbVie, and our licenseagreement with Gilead Sciences, Inc., or Gilead;•our expectations regarding milestones, option-related fees and other contingent payments under our collaborationagreement with AbbVie and our license agreement with Gilead;•the potential receipt of up to $36.2 million in additional gross proceeds in the second half of 2026 if all of the Series Ccommon stock warrants issued in connection with our June 2025 follow-on offering are exercised at their currentexercise price of $10.50 per warrant;•our ability to secure additional capital in the future;•the potential advantages and benefits of our current and future product candidates, including our beliefs regarding thepotential benefits of our current and future product candidates in combination with other agents;•our strategic plans to research, develop and, if approved, subsequently commercialize any product candidates we maydevelop;•our ability to identify additional products, product candidates or technologies with significant potential that areconsistent with our research, development and commercial objectives;•our manufacturing capabilities and strategy, including our reliance on third parties to manufacture our current or futureproduct candidates;•our expectations regarding our ability to obtain and maintain intellectual property protectio