Xilio Therapeutics, Inc. 10-Q

Item 5. Other Information (a) Departure of Chief Medical Officer On May 11, 2026, Katarina Luptakova, M.D., notified us of her decision to resign as chief medical officer effective May 31, 2026 to pursue other opportunities. We have engaged Martin Huber, M.D., to serve as a medical and clinical consultant on an interim basis. Dr. Huber most recently served as president and chief executive officer of Mersana Therapeutics, Inc. (prior to its acquisition by Day One Biopharmaceuticals, Inc.), and prior to that served as president and head of R&D at Xilio. Appointment of Principal Accounting Officer On May 11, 2026, our board of directors appointed Christopher Frankenfield, our chief operating and financial officer and principal financial officer, to also serve as our principal accounting officer effective as of that date. Upon Mr. Frankenfield’s appointment, our former principal accounting officer ceased to serve in such role. Christopher Frankenfield, age 44, has served as our chief financial officer since August 2024 and our chief operating officer since August 2023. Mr. Frankenfield previously served as our chief legal and administrative officer from August 2022 to August 2023 and as our general counsel from March 2021 to August 2022. Prior to joining us, Mr. Frankenfield served in roles of increasing responsibility 100 Table of Contents at Blueprint Medicines Corporation, or Blueprint, from August 2015 to March 2021, including as vice president of corporate legal affairs from July 2019 to March 2021. While at Blueprint, Mr. Frankenfield was responsible for a range of corporate legal activities, including public company reporting, capital markets strategy and follow-on equity offerings, collaborations and partnerships, and supporting commercial product launches. Prior to joining Blueprint, Mr. Frankenfield was a senior associate at Wilmer Cutler Pickering Hale and Dorr LLP, where his practice focused on capital markets and strategic transactions, public company reporting and corporate governance matters. Mr. Frankenfield began his career in the advisory practice at PricewaterhouseCoopers LLP. He received his B.A. in economics from the College of William & Mary and his J.D. from the University of Virginia School of Law. Mr. Frankenfield does not have a family relationship with any of our officers or directors and has no direct or indirect interest in any transaction required to be disclosed pursuant to Item 404(a) of Regulation S-K. There have been no changes to Mr. Frankenfield’s compensatory plans or arrangements in connection with his appointment described herein. (c) Director and Officer Trading Arrangements None of our directors or officers adopted or terminated a Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement (as such terms are defined in Items 408(a) and 408(c) of Regulation S-K, respectively) during the quarterly period covered by this Quarterly Report on Form 10-Q. 101 Table of Contents Item 6. Exhibits EXHIBIT INDEX Exhibit Number Description 3.1 Restated Certificate of Incorporation of the Registrant, as amended (incorporated by reference to Exhibit 3.1 to the Registrant's Form 10-K (File No. 001-40925), filed with the Securities and Exchange Commission on March 23, 2026) 3.2 Second Amended and Restated Bylaws of the Registrant (incorporated by reference to Exhibit 3.1 to the Registrant’s Current Report on Form 8-K (File No. 001-40925), filed with the Securities and Exchange Commission on April 3, 2023) 4.1 Form of Pre-Funded Warrant Agreement (incorporated by reference to Exhibit 4.1 to the Registrant’s Current Report on form 8-K (File No. 001-40925), filed with the Securities and Exchange Commission on February 12, 2026) 10.1 Underwriting Agreement, dated February 11, 2026, by and between Xilio Therapeutics, Inc. and Leerink Partners LLC, as representative of the underwriter named therein (incorporated by reference to Exhibit 1.1 to the Registrant’s Current Report on form 8-K (File No. 001-40925), filed with the Securities and Exchange Commission on February 12, 2026) 10.2 Second Amended and Restated 2022 Inducement Stock Incentive Plan (incorporated by reference to Exhibit 10.9 to the Registrant's Annual Report on Form 10-K (File No. 001-40925) filed with the Securities and Exchange Commission on March 23, 2026) 10.3 Amended and Restated Employment Agreement, dated January 1, 2026, by and between the Registrant and René Russo (incorporated by reference to Exhibit 10.15 to the Registrant’s Annual Report on Form 10-K (File No. 001-40925) filed with the Securities and Exchange Commission on March 23, 2026) 31.1* Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 31.2* Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 32.1+ Certifications of Principal Executive Officer and Principal Financial Officer Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 200 2 101.INS* XBRL Instance Document – the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document 101.SCH* Inline XBRL Taxonomy Extension Schema with Embedded Linkbase Document 104 Cover Page Interactive Data File (formatted as Inline XBRL with applicable taxonomy extension information contained in Exhibits 101) * Filed herewith. + The certifications attached as Exhibit 32.1 are being furnished solely to accompany this Quarterly Report on Form 10-Q and will not be deemed to be “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to the liability of that section. Such certifications will not be deemed to be incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except to the extent that the Registrant specifically incorporates it by reference into such filing. 102 Table of Contents 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 thereunto duly authorized. XILIO THERAPEUTICS, INC. Date: May 12, 2026 By: /s/ René Russo René Russo, Pharm.D. President and Chief Executive Officer (Principal Executive Officer) Date: May 12, 2026 By: /s/ Christopher Frankenfield Christopher Frankenfield Chief Financial Officer and Chief Operating Officer (Principal Financial and Accounting Officer) 103