XLO / Xilio Therapeutics, Inc. - Pemfailan SEC, Laporan Tahunan, Penyata Proksi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 22, 2025 Xilio Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 22, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 14, 2025 Xilio Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 14, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fi

Restated Certificate of Incorporation of the Registrant, as amended

EXHIBIT 3.1 RESTATED CERTIFICATE OF INCORPORATION OF XILIO THERAPEUTICS, INC. Xilio Therapeutics, Inc., a corporation organized and existing under the General Corporation Law of the State of Delaware (the “Corporation”), does hereby certify that the name of the Corporation is Xilio Therapeutics, Inc. and the original certificate of incorporation of the corporation was filed with the Secretary of S

Xilio Therapeutics Announces Pipeline and Business Updates and Second Quarter 2025 Financial Results Announced updated Phase 2 data at ASCO for vilastobart, a tumor-activated, Fc-enhanced, anti-CTLA-4, demonstrating deep and durable responses and a m

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Second Quarter 2025 Financial Results Announced updated Phase 2 data at ASCO for vilastobart, a tumor-activated, Fc-enhanced, anti-CTLA-4, demonstrating deep and durable responses and a meaningfully differentiated safety and tolerability profile for an anti-CTLA-4 combination therapy On track with plans to nominate first d

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 10, 2025 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 10, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 10, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 2, 2025 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 2, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Pre-Funded Warrants to Purchase 66,676,000 Shares of Common Stock Series A Warrants to Purchase 66,676,000 Shares of Common Stock (or Pre-Funded Warrants) Series B Warrants to Purchase 66,676,000 Shares of Common Stock (or Pre-Funded Warrants) Series

Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-285703 PROSPECTUS SUPPLEMENT (To Prospectus dated May 8, 2025) Pre-Funded Warrants to Purchase 66,676,000 Shares of Common Stock Series A Warrants to Purchase 66,676,000 Shares of Common Stock (or Pre-Funded Warrants) Series B Warrants to Purchase 66,676,000 Shares of Common Stock (or Pre-Funded Warrants) Series C Warrants to

Xilio Therapeutics Announces Pricing of $50.0 Million Public Offering

Exhibit 99.1 Xilio Therapeutics Announces Pricing of $50.0 Million Public Offering WALTHAM, Mass., June 2, 2025 — Xilio Therapeutics, Inc. (Nasdaq: XLO), a clinical-stage biotechnology company discovering and developing tumor-activated immuno-oncology therapies for people living with cancer, today announced the pricing of an underwritten public offering of pre-funded warrants to purchase 66,676,00

Form of Series A, Series B and Series C Warrant Agreement

Exhibit 4.2 THE ISSUER HAS FILED A REGISTRATION STATEMENT (INCLUDING A PROSPECTUS) WITH THE COMMISSION FOR THE OFFERING TO WHICH THIS COMMUNICATION RELATES. BEFORE YOU INVEST, YOU SHOULD READ THE PROSPECTUS IN THAT REGISTRATION STATEMENT AND OTHER DOCUMENTS THE ISSUER HAS FILED WITH THE COMMISSION FOR MORE COMPLETE INFORMATION ABOUT THE ISSUER AND THIS OFFERING. YOU MAY GET THESE DOCUMENTS FOR FRE

Underwriting Agreement, dated June 2, 2025, by and between Xilio Therapeutics, Inc. and Leerink Partners LLC, as representative of the underwriter named therein

Exhibit 1.1 PRE-FUNDED WARRANTS TO PURCHASE 66,676,000 SHARES OF COMMON STOCK SERIES A WARRANTS TO PURCHASE 66,676,000 SHARES OF COMMON STOCK (OR, IN LIEU OF COMMON STOCK, PRE-FUNDED WARRANTS TO PURCHASE COMMON STOCK) SERIES B WARRANTS TO PURCHASE 66,676,000 SHARES OF COMMON STOCK (OR, IN LIEU OF COMMON STOCK, PRE-FUNDED WARRANTS TO PURCHASE COMMON STOCK) SERIES C WARRANTS TO PURCHASE 66,676,000 S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

Form of Pre-Funded Warrant Agreement

EX-4.1 Exhibit 4.1 THE ISSUER HAS FILED A REGISTRATION STATEMENT (INCLUDING A PROSPECTUS) WITH THE COMMISSION FOR THE OFFERING TO WHICH THIS COMMUNICATION RELATES. BEFORE YOU INVEST, YOU SHOULD READ THE PROSPECTUS IN THAT REGISTRATION STATEMENT AND OTHER DOCUMENTS THE ISSUER HAS FILED WITH THE COMMISSION FOR MORE COMPLETE INFORMATION ABOUT THE ISSUER AND THIS OFFERING. YOU MAY GET THESE DOCUMENTS

Subject to Completion, dated June 2, 2025

Table of Contents The information in this preliminary prospectus supplement is not complete and may be changed.

Xilio Therapeutics Announces Updated Phase 2 Data for Vilastobart, a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Metastatic Microsatellite Stable Colorectal Cancer 26% preliminary objective response rate observed in

Exhibit 99.2 Xilio Therapeutics Announces Updated Phase 2 Data for Vilastobart, a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Metastatic Microsatellite Stable Colorectal Cancer 26% preliminary objective response rate observed in heavily pre-treated patients with metastatic microsatellite stable colorectal cancer (MSS CRC) without liver metastases Deep and durable

Unleashing the Potential of Immuno-Oncology Therapies May 31, 2025 © 2025 Xilio Therapeutics, Inc.

Exhibit 99.1 Unleashing the Potential of Immuno-Oncology Therapies May 31, 2025 © 2025 Xilio Therapeutics, Inc. Forward-Looking Statements and Disclaimers This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: developm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 31, 2025 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 31, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Collaboration, License and Option Agreement, dated February 10, 2025, between Xilio Development, Inc. and AbbVie Group Holdings Limited

Exhibit 10.1 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. Collaboration, License and Option Agreement By and among Xilio Development, Inc. and AbbVie Group Holdings Limited Dated as of February 10, 2025 TABLE OF CONTE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001

Investor Rights Agreement, dated February 10, 2025, between the Registrant and AbbVie Inc.

Exhibit 10.3 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. Xilio Therapeutics, Inc. INVESTOR RIGHTS AGREEMENT This Investor Rights Agreement (this “Agreement”) is dated as of February 10, 2025, by and between Xilio The

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 8, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File N

Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2025 Financial Results Updated Phase 2 data to be presented at ASCO for vilastobart, a tumor-activated, Fc-enhanced, anti-CTLA-4, in combination with atezolizumab in patient

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2025 Financial Results Updated Phase 2 data to be presented at ASCO for vilastobart, a tumor-activated, Fc-enhanced, anti-CTLA-4, in combination with atezolizumab in patients with metastatic microsatellite stable colorectal cancer (MSS CRC) Advancing multiple masked T cell engager programs utilizing Xilio’s n

Common Stock Purchase Agreement, dated February 10, 2025, between the Registrant and AbbVie Inc.

Exhibit 10.2 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. XILIO THERAPEUTICS, INC. COMMON STOCK PURCHASE AGREEMENT This Common Stock Purchase Agreement (this “Agreement”) is dated as of February 10, 2025, by and betwe

As filed with the Securities and Exchange Commission on May 6, 2025

As filed with the Securities and Exchange Commission on May 6, 2025 Registration No.

May 6, 2025

May 6, 2025 VIA EDGAR SUBMISSION U.S. Securities and Exchange Commission Division of Corporation Finance, Office of Life Sciences 100 F Street, NE Washington, DC 20549 Attention: Alan Campbell Re: Xilio Therapeutics, Inc. Registration Statement on Form S-3 Filed March 11, 2025 File No. 333-285703 Request for Acceleration Ladies and Gentlemen: Pursuant to Rule 461 under the Securities Act of 1933,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 4, 2025 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 4, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Xilio Therapeutics Announces Pipeline and Business Updates and Fourth Quarter and Full Year 2024 Financial Results Additional Phase 2 data for vilastobart, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Fourth Quarter and Full Year 2024 Financial Results Additional Phase 2 data for vilastobart, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with MSS CRC anticipated in the middle of 2025 Advancing masked T cell engager programs in novel ATACR and SEECR formats for PSMA, CLDN18.2 an

As filed with the Securities and Exchange Commission on March 11, 2025

Table of Contents As filed with the Securities and Exchange Commission on March 11, 2025 Registration No.

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 11, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fil

Sales Agreement, dated as of March 11, 2025, by and between the Registrant and Leerink Partners, LLC (incorporated by reference to Exhibit 1.1 to the Registrant’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on March 11, 2025)

Exhibit 1.1 XILIO THERAPEUTICS, INC. SHARES OF COMMON STOCK SALES AGREEMENT March 11, 2025 LEERINK PARTNERS LLC 1301 Avenue of the Americas, 5th Floor New York, New York 10019 Ladies and Gentlemen: Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), confirms its agreement (this “Agreement”) with Leerink Partners LLC (“Leerink Partners”), as follows: 1. Issuance and Sale of Shares. Th

Up to $50,000,000 Common Stock

424B5 1 d896243d424b5.htm 424B5 Table of Contents Filed pursuant to Rule 424(b)(5) Registration No. 333-268264 PROSPECTUS SUPPLEMENT (To Prospectus dated November 18, 2022) Up to $50,000,000 Common Stock We have entered into a sales agreement (sales agreement) with Leerink Partners LLC (Leerink Partners) dated March 11, 2025, relating to shares of our common stock offered by this prospectus supple

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number: 001-40925 Xilio

Form of Senior Indenture

Exhibit 4.3 XILIO THERAPEUTICS, INC. and Trustee INDENTURE Dated as of SENIOR DEBT SECURITIES CROSS-REFERENCE TABLE1 Section of Trust Indenture Act of 1939, as amended Section of Indenture 310(a) 6.09 310(b) 6.08 6.10 310(c) Inapplicable 311(a) 6.13 311(b) 6.13 311(c) Inapplicable 312(a) 4.01 4.04 312(b) 4.04(c) 312(c) 4.04(c) 313(a) 4.03 313(b) 4.03 313(c) 4.03 313(d) 4.03 314(a) 4.02 314(b) Inap

Amended and Restated 2022 Inducement Stock Incentive Plan

Exhibit 10.9 Xilio Therapeutics, Inc. AMENDED AND RESTATED 2022 INDUCEMENT STOCK INCENTIVE PLAN 1.Purpose The purpose of this Amended and Restated 2022 Inducement Stock Incentive Plan (the “Plan”) of Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain and motivate persons w

Form of Subordinated Note

Exhibit 4.6 Form of Subordinated Note (FACE OF SECURITY) [Each Global Security shall bear substantially the following legend: UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE REGISTERED FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE

Form of Senior Note

Exhibit 4.5 Form of Senior Note (FACE OF SECURITY) [Each Global Security shall bear substantially the following legend: UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE REGISTERED FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Xilio Therapeutics, Inc.

Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 11, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fil

Xilio Therapeutics Insider Trading Policy

Exhibit 19 XILIO THERAPEUTICS, INC. Insider Trading Policy Amended and Restated Effective:August 3, 2023 1. Background and purpose 1.1Why Have We Adopted This Policy? The federal securities laws prohibit any member of the Board of Directors (each, a “director”), officer (as defined in Rule 16a-1(f) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), an “executive officer”)

Form of Subordinated Indenture

Exhibit 4.4 XILIO THERAPEUTICS, INC. and Trustee INDENTURE Dated as of SUBORDINATED DEBT SECURITIES CROSS-REFERENCE TABLE1 Section of Trust Indenture Act of 1939, as amended Section of Indenture 310(a) 6.09 310(b) 6.08 6.10 310(c) Inapplicable 311(a) 6.13 311(b) 6.13 311(c) Inapplicable 312(a) 4.01 4.04 312(b) 4.04(c) 312(c) 4.04(c) 313(a) 4.03 313(b) 4.03 313(c) 4.03 313(d) 4.03 314(a) 4.02 314(b

As filed with the Securities and Exchange Commission on March 11, 2025

As filed with the Securities and Exchange Commission on March 11, 2025 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Xilio Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 10, 2025 Xilio Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 10, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission

AbbVie and Xilio Therapeutics Announce Collaboration and Option Agreement to Develop Novel Tumor-Activated Immunotherapies

Exhibit 99.1 AbbVie and Xilio Therapeutics Announce Collaboration and Option Agreement to Develop Novel Tumor-Activated Immunotherapies · Collaboration will combine AbbVie’s oncology expertise and Xilio’s proprietary tumor-activation technology to develop novel immunotherapies, including masked T-cell engagers · Xilio to host investor conference call and webcast today at 8:30 am EST NORTH CHICAGO,

Xilio Therapeutics Announces Multiple Masked T Cell Engager Programs Also entered into collaboration and option agreement with AbbVie to develop novel tumor-activated immunotherapies, including masked T cell engagers, with $52.0 million in upfront pa

Exhibit 99.2 Xilio Therapeutics Announces Multiple Masked T Cell Engager Programs Also entered into collaboration and option agreement with AbbVie to develop novel tumor-activated immunotherapies, including masked T cell engagers, with $52.0 million in upfront payments Extended anticipated cash runway into the first quarter of 2026 Company to host investor conference call and webcast today at 8:30

2 This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: plans and a

1 Unleashing the Potential of Immuno-Oncology Therapies January 21, 2025 © 2025 Xilio Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 21, 2025 Xilio Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 21, 2025 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission F

Xilio Therapeutics Announces Initial Phase 2 Data for Vilastobart (XTX101), a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Metastatic Microsatellite Stable Colorectal Cancer 27% preliminary response rate observed in

Exhibit 99.2 Xilio Therapeutics Announces Initial Phase 2 Data for Vilastobart (XTX101), a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Metastatic Microsatellite Stable Colorectal Cancer 27% preliminary response rate observed in heavily pre-treated microsatellite stable colorectal cancer (MSS CRC) patients without liver metastases Responses were accompanied by dec

Xilio Therapeutics to Present Initial Phase 2 Data for Vilastobart (XTX101), a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Metastatic Microsatellite Stable Colorectal Cancer at ASCO GI Announces preliminary Phase 1

Exhibit 99.2 Xilio Therapeutics to Present Initial Phase 2 Data for Vilastobart (XTX101), a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Metastatic Microsatellite Stable Colorectal Cancer at ASCO GI Announces preliminary Phase 1 data for XTX301, a tumor-activated IL-12, demonstrating an improved tolerability profile over historical data for rhIL-12, with no dose-l

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 18, 2024 Xilio Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 18, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission

2 This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: plans and a

Exhibit 99.1 1 Unleashing the Potential of Immuno-Oncology Therapies December 19, 2024 © 2024 Xilio Therapeutics, Inc. 2 This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: plans and anticipated milestones for vilas

XLO / Xilio Therapeutics, Inc. / Bain Capital Life Sciences Fund II, L.P. - SC 13G/A Passive Investment

SC 13G/A 1 d909949dsc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G (Rule 13d-102) Information to be Included in Statements Filed Pursuant to § 240.13d-1(b), (c) and (d) and Amendments Thereto Filed Pursuant to § 240.13d-2 Under the Securities Exchange Act of 1934 (Amendment No. 2) XILIO THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001

AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13G

EX-99.A 2 d909949dex99a.htm EX-99.A Exhibit A AGREEMENT REGARDING THE JOINT FILING OF SCHEDULE 13G The undersigned hereby agree as follows: i. Each of them is individually eligible to use the Schedule 13G to which this Exhibit is attached, and such Schedule 13G is filed on behalf of each of them; and ii. Each of them is responsible for the timely filing of such Schedule 13G and any amendments ther

XLO / Xilio Therapeutics, Inc. / Atlas Venture Fund XI, L.P. - SC 13G/A Passive Investment

SC 13G/A 1 tm2428252d3sc13ga.htm SC 13G/A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No.1)* XILIO THERAPEUTICS, Inc. (Name of Issuer) COMMON STOCK, $0.0001 PAR VALUE (Title of Class of Securities) 98422T100 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of This Statement) Check

XLO / Xilio Therapeutics, Inc. / Rock Springs Capital Management LP Passive Investment

SC 13G/A 1 rocksprings-xlo093024a2.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Schedule 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement)

Xilio Therapeutics Announces Pipeline and Business Updates and Third Quarter 2024 Financial Results Will present initial Phase 1C dose escalation data for vilastobart (XTX101), a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizu

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Third Quarter 2024 Financial Results Will present initial Phase 1C dose escalation data for vilastobart (XTX101), a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab, in a late-breaker poster presentation at the SITC Annual Meeting Expect to report initial Phase 2 data in microsatellite stable colo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 7, 2024 Xilio Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 7, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission F

Xilio Therapeutics Announces Initial Clinical Trial Data from Phase 1C Dose Escalation for Vilastobart (XTX101), a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Advanced Solid Tumors Combination of vilastobart and ate

Exhibit 99.3 Xilio Therapeutics Announces Initial Clinical Trial Data from Phase 1C Dose Escalation for Vilastobart (XTX101), a Tumor-Activated Anti-CTLA-4, in Combination with Atezolizumab in Patients with Advanced Solid Tumors Combination of vilastobart and atezolizumab demonstrated encouraging early evidence of anti-tumor activity, including unconfirmed partial responses observed in two patient

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number:

2 This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: plans and a

Exhibit 99.2 1 Unleashing the Potential of Immuno-Oncology Therapies November 7, 2024 © 2024 Xilio Therapeutics, Inc. 2 This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: plans and anticipated milestones for vilast

XLO / Xilio Therapeutics, Inc. / GKCC, LLC - GKCC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) June 7, 2024 (Date of Event which Requires Filing of this Statement) Check the appropriate box to designate the rul

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 10, 2024 Xilio Therapeu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 10, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission

Third Amended and Restated Employment Agreement, dated August 3, 2024, by and between the Registrant and Christopher Frankenfield

Exhibit 10.2 THIRD AMENDED AND RESTATED EMPLOYMENT AGREEMENT THIS THIRD AMENDED AND RESTATED EMPLOYMENT AGREEMENT (the “Agreement”) is made as of August 3, 2024 (the “Effective Date”) by and between Xilio Therapeutics, Inc. (the “Company”) and Christopher Frankenfield (the “Executive”) (together, the “Parties”). RECITALS WHEREAS, the Company and the Executive are party to an Employment Agreement,

Xilio Therapeutics Announces Pipeline and Business Updates and Second Quarter 2024 Financial Results Initiated enrollment in Phase 2 clinical trial of XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients wi

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Second Quarter 2024 Financial Results Initiated enrollment in Phase 2 clinical trial of XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with microsatellite stable colorectal cancer (MSS CRC) Initiated enrollment in Phase 1B monotherapy dose expansion for XTX301, a tumor-acti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 8, 2024 Xilio Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 8, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fil

XLO / Xilio Therapeutics, Inc. / TAKEDA PHARMACEUTICAL CO LTD - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 – Exit Filing)* XILIO THERAPEUTICS, INC. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) July 31, 20241 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to

Identification of the subsidiary which acquired the security being reported on by the parent holding compan

Exhibit 99.1 Identification of the subsidiary which acquired the security being reported on by the parent holding company. Takeda Pharmaceutical Company Limited’s (“Takeda”) beneficial ownership of the issuer’s common stock (“Common Stock”) consists of 1,475,121 shares of Common Stock held by Takeda Ventures, Inc. (“TVI”). TVI is wholly owned directly by Takeda Pharmaceuticals U.S.A., Inc., which

Joint Filing Agreement

Exhibit 99.2 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, the undersigned agree to the joint filing of a Statement on Schedule 13G (including any and all amendments thereto) with respect to the Common Stock of Xilio Therapeutics, Inc. and further agree to the filing of this agreement as an Exhibit thereto. In addition, each party

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 13, 2024 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 13, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 13, 2024 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 13, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2024 Financial Results Expect to initiate Phase 2 trial for XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with microsatell

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2024 Financial Results Expect to initiate Phase 2 trial for XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with microsatellite stable colorectal cancer (MSS CRC) in the third quarter of 2024 Plan to report clinical data for XTX101 and XTX301, a tumor-activated

Amended and Restated Non-Employee Director Compensation Policy

Exhibit 10.6 XILIO THERAPEUTICS, INC. AMENDED AND RESTATED DIRECTOR COMPENSATION POLICY Effective: April 16, 2024 The non-employee directors of Xilio Therapeutics, Inc. (the “Company”) shall receive the following compensation for their service as members of the Board of Directors (the “Board”) of the Company. Director Compensation Our goal is to provide compensation for our non-employee directors

Common Stock Purchase Agreement, dated March 27, 2024, between the Registrant and Gilead Sciences, Inc.

Exhibit 10.2 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. XILIO THERAPEUTICS, INC. COMMON STOCK PURCHASE AGREEMENT This Common Stock Purchase Agreement (this “Agreement”) is dated as of March 27, 2024, by and between

Investor Rights Agreement, dated March 27, 2024, between the Registrant and Gilead Sciences, Inc.

Exhibit 10.3 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. Xilio Therapeutics, Inc. INVESTOR RIGHTS AGREEMENT This Investor Rights Agreement (this “Agreement”) is made as of March 27, 2024, by and between Xilio Therape

License Agreement, dated March 27, 2024, between Xilio Development, Inc. and Gilead Sciences, Inc.

Exhibit 10.1 Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. LICENSE AGREEMENT between Xilio DEVELOPMENT, Inc. and GILEAD SCIENCES, INC. Dated as of March 27, 2024 TABLE OF CONTENTS ARTICLE 1 DEFINITIONS‌1 ARTICLE 2 GOVE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001

May 2, 2024

May 2, 2024 VIA EDGAR SUBMISSION Securities and Exchange Commission Division of Corporation Finance 100 F Street, NE Washington, DC 20549 Attention: Tim Buchmiller Re: Xilio Therapeutics, Inc.

As filed with the Securities and Exchange Commission on April 30, 2024

Table of Contents As filed with the Securities and Exchange Commission on April 30, 2024 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Xilio Therapeutics, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14

Up to $18,720,000 XILIO THERAPEUTICS, INC. Common Stock

PROSPECTUS SUPPLEMENT (To Prospectus dated November 18, 2022) Filed Pursuant to Rule 424(b)(5) Registration No.

XLO / Xilio Therapeutics, Inc. / Rock Springs Capital Management LP Passive Investment

SC 13G/A 1 rocksprings-xlo032724a1.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Schedule 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1)* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) March 27, 2024 (Date of Event Which Requires Filing of this Statement) Chec

XLO / Xilio Therapeutics, Inc. / GILEAD SCIENCES INC - SC 13G Passive Investment

SC 13G 1 d824908dsc13g.htm SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) March 27, 2024 (Date of Event Which Requires Filing of this Statement) Check the

Subsidiaries of the Registrant

Exhibit 21.1 Subsidiaries of the Registrant Entity Jurisdiction of Incorporation Xilio Securities Corporation Massachusetts Xilio Development, Inc. Delaware

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 1, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Xilio Therapeutics, Inc.

Executive Compensation Clawback Policy

Exhibit 97 XILIO THERAPEUTICS, INC. Executive Compensation Clawback Policy Effective Date: October 2, 2023 Approved and Adopted: November 14, 2023 The board of directors (the “Board”) of Xilio Therapeutics, Inc. (the “Company”) has adopted this executive compensation clawback policy (this “Policy”), in accordance with Nasdaq Listing Rule 5608 (“Rule 5608”). 1.Definitions (a)“Accounting Restatement

As filed with the Securities and Exchange Commission on April 1, 2024

As filed with the Securities and Exchange Commission on April 1, 2024 Registration No.

Xilio Therapeutics Announces Pipeline and Business Updates and Fourth Quarter and Full Year 2023 Financial Results On track with plans to initiate Phase 2 trial for XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Fourth Quarter and Full Year 2023 Financial Results On track with plans to initiate Phase 2 trial for XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab in patients with microsatellite stable colorectal cancer (MSS CRC) in the third quarter of 2024 Granted Gilead exclusive license to devel

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number: 001-40925 Xilio

Employment Agreement, dated September 5, 2023, by and between the Registrant and Katarina Luptakova, M.D

Exhibit 10.18 EMPLOYMENT AGREEMENT This Employment Agreement (the “Agreement”) is entered into as of September 5, 2023 (the “Effective Date”) by and between Xilio Therapeutics, Inc. (the “Company”) and Katarina Luptakova, M.D. (the “Executive”) (together, the “Parties”). RECITALS WHEREAS, the Company and the Executive are party to an offer letter dated October 26, 2021 (the “Existing Offer Letter”

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 28, 2024 Xilio Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 28, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fil

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 27, 2024 Xilio Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 27, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fil

Form of Prefunded Warrant

Exhibit 4.1 THESE SECURITIES REPRESENTED HEREBY AND THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES HAVE NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE BUT HAVE BEEN OR WILL BE ISSUED IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND, ACCORDINGLY, MAY NOT BE TRANSFERRED UNLESS (I) S

Xilio Therapeutics Announces $11.3 Million Private Placement Equity Financing Announces strategic portfolio reprioritization focused on rapid advancement of clinical-stage programs for XTX301, a tumor-activated, IL-12, and XTX101, a tumor-activated,

Exhibit 99.2 Xilio Therapeutics Announces $11.3 Million Private Placement Equity Financing Announces strategic portfolio reprioritization focused on rapid advancement of clinical-stage programs for XTX301, a tumor-activated, IL-12, and XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, and leveraging the company’s promising research platform for tumor-activated bispecific and cell engager molecul

Gilead and Xilio Announce Exclusive License Agreement for Tumor-Activated IL-12 Program -- Gilead Granted Exclusive License to Xilio’s Tumor-Activated IL-12 Program, Including XTX301, a Clinical-Stage IL-12 Molecule with Potential to Treat a Broad Ra

Exhibit 99.1 CONTACTS Xilio Info Investors: Melissa Forst Argot Partners [email protected] Media: Dan Budwick 1AB [email protected] Gilead Info Investors: Jacquie Ross [email protected] Media: Meaghan Smith [email protected] Gilead and Xilio Announce Exclusive License Agreement for Tumor-Activated IL-12 Program - Gilead Granted Exclusive License to Xilio’s Tumor-Activated IL

Registration Rights Agreement, dated March 28, 2024, among the Registrant and the persons party thereto

Exhibit 10.2 Execution Version REGISTRATION RIGHTS AGREEMENT This REGISTRATION RIGHTS AGREEMENT (this “Agreement”) is made and entered into as of March 28, 2024 by and among Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), and the “Investors” named in that certain Securities Purchase Agreement by and among the Company and the Investors, dated as of the date hereof (the “Purchase A

Securities Purchase Agreement, dated March 28, 2024, among the Registrant and the persons party thereto

Exhibit 10.1 Execution Version SECURITIES PURCHASE AGREEMENT This SECURITIES PURCHASE AGREEMENT (this “Agreement”) is made and entered into as of March 28, 2024 (the “Execution Date”) by and among Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), and the Investors identified on Exhibit A attached hereto (each an “Investor” and collectively the “Investors”). RECITALS A.The Company a

XLO / Xilio Therapeutics, Inc. / Rock Springs Capital Management LP Passive Investment

SC 13G 1 rocksprings-xlo123123.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check th

XLO / Xilio Therapeutics, Inc. / Octagon Capital Advisors LP - AMENDMENT NO. 2 Passive Investment

SC 13G/A 1 j21244sc13ga2.htm AMENDMENT NO. 2 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* XILIO THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 Par Value (Title of Class of Securities) 98422T100 (CUSIP Number) 01/02/2024 (Date of Event Which Requires Filing of This Statement) Check the ap

XLO / Xilio Therapeutics, Inc. / Octagon Capital Advisors LP - AMENDMENT NO. 1 Passive Investment

SC 13G/A 1 o15240sc13ga1.htm AMENDMENT NO. 1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* XILIO THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 Par Value (Title of Class of Securities) 98422T100 (CUSIP Number) 12/31/2023 (Date of Event Which Requires Filing of This Statement) Check the ap

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 19, 2024 Xilio Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 19, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission F

Form of Restricted Unit Agreement under the 2021 Stock Incentive Plan

Exhibit 10.1 Xilio Therapeutics, Inc. RESTRICTED STOCK UNIT AGREEMENT Granted under 2021 Stock Incentive Plan Xilio Therapeutics, Inc. (the “Company”) hereby grants the following restricted stock units to the recipient named below pursuant to the Company’s 2021 Stock Incentive Plan (as amended through the date hereof, the “Plan”). The terms and conditions attached hereto are also a part hereof and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 1, 2024 Xilio Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 1, 2024 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fi

Xilio Therapeutics Announces Initiation of Enrollment for Phase 1 Combination Trial of XTX101, a Tumor-Activated, Fc-Enhanced Anti-CTLA-4, and Updated Phase 1 Monotherapy Data Phase 1 combination dose escalation expected to support planned Phase 2 tr

Exhibit 99.1 Xilio Therapeutics Announces Initiation of Enrollment for Phase 1 Combination Trial of XTX101, a Tumor-Activated, Fc-Enhanced Anti-CTLA-4, and Updated Phase 1 Monotherapy Data Phase 1 combination dose escalation expected to support planned Phase 2 trial in microsatellite stable colorectal cancer (MSS CRC) Updated Phase 1 monotherapy data for XTX101 at the recommended Phase 2 dose (RP2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 7, 2023 Xilio Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 7, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment No. 1) (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 00

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K/A (Amendment No. 1) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number: 001-40925 Xil

Xilio Therapeutics Announces Pipeline and Business Updates and Third Quarter 2023 Financial Results Demonstrated initial clinical validation of tumor-selective activation technology for both XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, and XTX

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Third Quarter 2023 Financial Results Demonstrated initial clinical validation of tumor-selective activation technology for both XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, and XTX202, a tumor-activated, beta-gamma IL-2 On track to activate trial sites for XTX101 dose escalation in combination with atezolizumab unde

Consulting Agreement, dated September 8, 2023, by and between the Registrant and Martin Huber, M.D.

Exhibit 10.3 CONSULTING AGREEMENT This Consulting Agreement (the “Agreement”), effective as of September 8, 2023 (the “Effective Date”), is entered into between Xilio Therapeutics, Inc. (the “Company”) and Martin Huber, M.D. (the “Consultant”). WHEREAS, the Company desires to retain the services of the Consultant and the Consultant desires to perform certain services for the Company; and WHEREAS,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A (Amendment No. 1) (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number:

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number:

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 9, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission F

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 3, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission F

Xilio Announces Initial Monotherapy Safety and Anti-Tumor Activity Data for XTX202, a Tumor-Activated, Engineered, Beta-Gamma IL-2, in Late Line Patients with Advanced Solid Tumors Initial evidence of dose-dependent disease control rate with 50% dise

Exhibit 99.1 Xilio Announces Initial Monotherapy Safety and Anti-Tumor Activity Data for XTX202, a Tumor-Activated, Engineered, Beta-Gamma IL-2, in Late Line Patients with Advanced Solid Tumors Initial evidence of dose-dependent disease control rate with 50% disease control rate at higher doses (≥2.8 mg/kg) and 31% disease control rate across all dose levels in a range of solid tumor types, includ

Xilio Therapeutics Announces Promotion of Katarina Luptakova, M.D., to Chief Medical Officer and Scott Coleman, Ph.D., to Chief Development Officer Martin Huber, M.D., to leave Xilio Therapeutics and remain an advisor

Exhibit 99.1 Xilio Therapeutics Announces Promotion of Katarina Luptakova, M.D., to Chief Medical Officer and Scott Coleman, Ph.D., to Chief Development Officer Martin Huber, M.D., to leave Xilio Therapeutics and remain an advisor WALTHAM, Mass., September 5, 2023 – Xilio Therapeutics, Inc. (Nasdaq: XLO), a clinical-stage biotechnology company discovering and developing tumor-activated immuno-onco

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 30, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fi

Employment Agreement, dated September 5, 2023, by and between the Registrant and Kevin Brennan

Exhibit 10.1 EMPLOYMENT AGREEMENT This Employment Agreement (the “Agreement”) is entered into as of September 5, 2023 (the “Effective Date”) by and between Xilio Therapeutics, Inc. (the “Company”) and Kevin Brennan (the “Executive”) (together, the “Parties”). RECITALS WHEREAS, the Company and the Executive are party to an offer letter dated March 15, 2023 (the “Existing Offer Letter”), and the Par

Amended and Restated Non-Employee Director Compensation Policy

Exhibit 10.1 XILIO THERAPEUTICS, INC. AMENDED AND RESTATED DIRECTOR COMPENSATION POLICY Effective: July 27, 2023 The non-employee directors of Xilio Therapeutics, Inc. (the “Company”) shall receive the following compensation for their service as members of the Board of Directors (the “Board”) of the Company. Director Compensation Our goal is to provide compensation for our non-employee directors i

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 14, 2023 Xilio Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 14, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-

Xilio Therapeutics Announces Pipeline and Business Updates and Second Quarter 2023 Financial Results Xilio entered into clinical trial collaboration with Roche to evaluate XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezol

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Second Quarter 2023 Financial Results Xilio entered into clinical trial collaboration with Roche to evaluate XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab (Tecentriq®), in patients with microsatellite stable (MSS) colorectal cancer Xilio to host live virtual program spotlighting XTX10

2 Forward-Looking Statements and Disclaimers This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timi

Exhibit 99.2 1 Unleashing the Potential of Immuno-Oncology Therapies August 14, 2023 © 2023 Xilio Therapeutics, Inc. 2 Forward-Looking Statements and Disclaimers This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: r

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 3, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fil

Second Amended and Restated Employment Agreement, dated August 3, 2023, by and between the Company and Christopher Frankenfield

Exhibit 10.1 SECOND AMENDED AND RESTATED EMPLOYMENT AGREEMENT THIS SECOND AMENDED AND RESTATED EMPLOYMENT AGREEMENT (the “Agreement”) is made as of August 3, 2023 (the “Effective Date”) by and between Xilio Therapeutics, Inc. (the “Company”) and Christopher Frankenfield (the “Executive”) (together, the “Parties”). RECITALS WHEREAS, the Company and the Executive are party to an Employment Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 8, 2023 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 8, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Xilio Therapeutics Announces Preliminary Clinical Data from Phase 1 Trial of XTX101, a Tumor-Activated, Fc-Enhanced Anti-CTLA-4, in Patients with Advanced Solid Tumors Encouraging preliminary anti-tumor activity observed in a patient with PD-L1 negat

Exhibit 99.2 Xilio Therapeutics Announces Preliminary Clinical Data from Phase 1 Trial of XTX101, a Tumor-Activated, Fc-Enhanced Anti-CTLA-4, in Patients with Advanced Solid Tumors Encouraging preliminary anti-tumor activity observed in a patient with PD-L1 negative advanced non-small cell lung cancer Favorable preliminary safety profile for XTX101 observed at the recommended Phase 2 dose of 150 m

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 25, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

2 Forward-Looking Statements and Disclaimers This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timi

Exhibit 99.1 1 Unleashing the Potential of Immuno-Oncology Therapies May 25, 2023 © 2023 Xilio Therapeutics, Inc. 2 Forward-Looking Statements and Disclaimers This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, timing and expectations related to: repo

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 9, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File N

Amended and Restated Loan and Security Agreement, dated as of May 5, 2023, by and between Xilio Development, Inc. and Pacific Western Bank

Exhibit 10.2 XILIO DEVELOPMENT, INC. AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT This AMENDED AND RESTATED LOAN AND SECURITY AGREEMENT (the “Agreement”) is entered into as of May 5, 2023, by and between PACIFIC WESTERN BANK, a California state chartered bank (“Bank”), and XILIO DEVELOPMENT, INC. (“Borrower”). RECITALS Borrower wishes to obtain credit from time to time from Bank, and Bank desi

Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2023 Financial Results Initiated Phase 2 clinical trial for XTX202, a tumor-activated IL-2 Anticipate reporting preliminary Phase 1 safety, PK, PD, and anti-tumor activity d

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2023 Financial Results Initiated Phase 2 clinical trial for XTX202, a tumor-activated IL-2 Anticipate reporting preliminary Phase 1 safety, PK, PD, and anti-tumor activity data for XTX101, a tumor-activated, Fc-enhanced anti-CTLA-4, in the second quarter of 2023 Ended first quarter of 2023 with $93.3 million

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Defin

Joint Filing Agreement

EX-99.1 2 ea176763ex99-1xiliothera.htm JOINT FILING AGREEMENT Exhibit 99.1 Joint Filing Agreement Pursuant to Rule 13d-1 This agreement is made pursuant to Rule 13d-l(k)(1) under the Securities and Exchange Act of 1934, as amended (the “Act”) by and among the parties listed below, each referenced to herein as a “Joint Filer.” The Joint Filers agree that a statement of beneficial ownership as requi

XLO / Xilio Therapeutics Inc / MRL Ventures Fund LLC - SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 ( )* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per shares (Title of Class of Securities) 98422T100 (CUSIP Number) March 30, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant

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)

Exhibit 3.1 SECOND AMENDED AND RESTATED BYLAWS OF XILIO THERAPEUTICS, INC. TABLE OF CONTENTS Page ARTICLE I STOCKHOLDERS 1 1.1 Place of Meetings 1 1.2 Annual Meeting 1 1.3 Special Meetings 1 1.4 Record Date for Stockholder Meetings 1 1.5 Notice of Meetings 1 1.6 Voting List 2 1.7 Quorum 2 1.8 Adjournments 2 1.9 Voting and Proxies 3 1.10 Action at Meeting 3 1.11 Nomination of Directors 3 1.12 Notic

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 28, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fil

Offer Letter, dated March 15, 2023 by and between the Registrant and Kevin Brennan (incorporated by reference to Exhibit 10.1 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)

Exhibit 10.1 March 15, 2023 Kevin Brennan Delivered via Email RE: Offer of Employment Dear Kevin, We are very excited to offer you the position of SVP, Finance and Accounting, with Xilio Development, Inc. (together with its affiliates, the “Company” or “Xilio”), where you will play an essential role in building Xilio’s long-term success. 1. Position. Your initial position with Xilio will be as SVP

Xilio Therapeutics Announces Pipeline and Business Updates for the Fourth Quarter and Full Year 2022 Financial Results Initial clinical data from XTX101, XTX202 and XTX301 clinical trials anticipated in 2023 XTX202, a tumor-activated IL-2, demonstrat

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates for the Fourth Quarter and Full Year 2022 Financial Results Initial clinical data from XTX101, XTX202 and XTX301 clinical trials anticipated in 2023 XTX202, a tumor-activated IL-2, demonstrated preliminary clinical pharmacodynamic evidence of tumor-selective activation, providing initial clinical platform validation Anticipate

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission file number: 001-40925 Xilio

Form of Restricted Stock Unit Agreement under the 2022 Inducement Stock Incentive Plan

Exhibit 10.10 Xilio Therapeutics, Inc. RESTRICTED STOCK UNIT AGREEMENT Granted under 2022 Inducement Stock Incentive Plan Xilio Therapeutics, Inc. (the “Company”) hereby grants the following restricted stock units to the recipient named below pursuant to the Company’s 2022 Inducement Stock Incentive Plan (as amended through the date hereof, the “Plan”). The terms and conditions attached hereto are

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-8 (Form Type) Xilio Therapeutics, Inc.

Form of Stock Option Agreement under the 2022 Inducement Stock Incentive Plan

Exhibit 10.9 Xilio Therapeutics, Inc. NONSTATUTORY STOCK OPTION AGREEMENT Granted under 2022 Inducement Stock Incentive Plan Xilio Therapeutics, Inc. (the “Company”) hereby grants the following stock option to the optionee named below pursuant to the Company’s 2022 Inducement Stock Incentive Plan (as amended through the date hereof, the “Plan”). The terms and conditions attached hereto are also a

2022 Inducement Stock Incentive Plan

Exhibit 10.8 Xilio Therapeutics, Inc. 2022 INDUCEMENT STOCK INCENTIVE PLAN 1.Purpose The purpose of this 2022 Inducement Stock Incentive Plan (the “Plan”) of Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain and motivate persons who are expected to make important contribu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 2, 2023 Xilio Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 2, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission File

Subsidiaries of the Registrant

Exhibit 21.1 Subsidiaries of the Registrant Entity Jurisdiction of Incorporation Xilio Securities Corporation Massachusetts Xilio Development, Inc. Delaware

As filed with the Securities and Exchange Commission on March 2, 2023

As filed with the Securities and Exchange Commission on March 2, 2023 Registration No.

US98422T1007 / Xilio Therapeutics, Inc. / Octagon Capital Advisors LP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* XILIO THERAPEUTICS, INC. (Name of Issuer) Common Stock, $0.0001 Par Value (Title of Class of Securities) 98422T100 (CUSIP Number) 12/31/2022 (Date of Event Which Requires Filing of This Statement) Check the appropriate box to designate the rule pursuant t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 9, 2023 Xilio Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 9, 2023 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission Fi

2 Forward - Looking Statements This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 , as amended, including, without limitation, statements regarding plans, timing and expe

EX-99.1 2 xlo-20230109xex99d1.htm EX-99.1 Exhibit 99.1 1 Unleashing the Potential of Immuno - Oncology Therapies January 9, 2023 © 2023 Xilio Therapeutics, Inc. 2 Forward - Looking Statements This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 , as amended, including, without limitation, statements regarding plans, timi

US98422T1007 / Xilio Therapeutics, Inc. / Flynn James E Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): December 19, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Com

Xilio Therapeutics, Inc. 828 Winter Street, Suite 300 Waltham, MA 02451 November 16, 2022

Xilio Therapeutics, Inc. 828 Winter Street, Suite 300 Waltham, MA 02451 November 16, 2022 VIA EDGAR SUBMISSION U.S. Securities and Exchange Commission Division of Corporation Finance, Office of Life Sciences 100 F Street, N.E. Washington, D.C. 20549 Attention: Christine Westbrook Re: Xilio Therapeutics, Inc. Registration Statement on Form S-3 File No. 333-268264 Request for Acceleration Ladies and

US98422T1007 / Xilio Therapeutics, Inc. / RA CAPITAL MANAGEMENT, L.P. - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 2)* XILIO THERAPEUTICS, INC. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) November 14, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate

Sales Agreement, dated September 9, 2022, by and between the Registrant and Cowen and Company, LLC

EX-1.2 2 tm2229768d2ex1-2.htm EXHIBIT 1.2 Exhibit 1.2 Xilio Therapeutics, Inc. $75,000,000 of shares of COMMON STOCK SALES AGREEMENT November 9, 2022 Cowen and Company, LLC 599 Lexington Avenue New York, NY 10022 Ladies and Gentlemen: Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), confirms its agreement (this “Agreement”) with Cowen and Company, LLC (“Cowen”), as follows: 1. Iss

Form of Subordinated Note

Exhibit 4.7 Form of Subordinated Note (FACE OF SECURITY) [Each Global Security shall bear substantially the following legend: UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE REGISTERED FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE

As filed with the Securities and Exchange Commission on November 9, 2022

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on November 9, 2022 Registration No.

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Xilio Therapeutics, Inc.

Xilio Therapeutics Announces Pipeline and Business Updates and Third Quarter 2022 Financial Results XTX202, a tumor-activated IL-2, successfully reached target dose range of 1 mg/kg in ongoing Phase 1 clinical trial; preliminary evidence of increased

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and Third Quarter 2022 Financial Results ? XTX202, a tumor-activated IL-2, successfully reached target dose range of 1 mg/kg in ongoing Phase 1 clinical trial; preliminary evidence of increased CD8+ effector T cells and NK cells observed with no signs of vascular leak syndrome ? XTX301, a tumor-activated IL-12, received FDA cl

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): November 9, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

2 Placeholder area for citations and references Forward - Looking Statements This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 , as amended, including, without limitatio

Exhibit 99.2 1 Placeholder area for citations and references Unleashing the Potential of Immuno - Oncology Therapies November 9, 2022 ? 2022 Xilio Therapeutics, Inc. 2 Placeholder area for citations and references Forward - Looking Statements This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 , as amended, including, w

Form of Subordinated Indenture

Exhibit 4.5 XILIO THERAPEUTICS, INC. and Trustee INDENTURE Dated as of SUBORDINATED DEBT SECURITIES CROSS-REFERENCE TABLE 1 Section of Trust Indenture Act of 1939, as amended Section of Indenture 310(a) 6.09 310(b) 6.08 6.10 310(c) Inapplicable 311(a) 6.13 311(b) 6.13 311(c) Inapplicable 312(a) 4.01 4.04 312(b) 4.04(c) 312(c) 4.04(c) 313(a) 4.03 313(b) 4.03 313(c) 4.03 313(d) 4.03 314(a) 4.02 314(

Form of Senior Indenture

Exhibit 4.4 XILIO THERAPEUTICS, INC. ?? and Trustee INDENTURE Dated as of SENIOR DEBT SECURITIES CROSS-REFERENCE TABLE1 Section of Trust Indenture Act of 1939, as amended Section of Indenture 310(a) 6.09 310(b) 6.08 6.10 310(c) Inapplicable 311(a) 6.13 311(b) 6.13 311(c) Inapplicable 312(a) 4.01 4.04 312(b) 4.04(c) 312(c) 4.04(c) 313(a) 4.03 313(b) 4.03 313(c) 4.03 313(d) 4.03 314(a) 4.02 314(b) I

Form of Senior Note

Exhibit 4.6 Form of Senior Note (FACE OF SECURITY) [Each Global Security shall bear substantially the following legend: UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE REGISTERED FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): September 15, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Co

Financial Statements and Exhibits, Results of Operations and Financial Condition

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): August 9, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commis

Xilio Therapeutics Announces Encouraging Preliminary Phase 1 Dose-Escalation Data for XTX101, a Tumor-Selective Anti-CTLA-4, and Reports Pipeline and Business Updates and Second Quarter 2022 Financial Results XTX101, tumor-selective anti-CTLA-4, has

Exibit 99.1 Xilio Therapeutics Announces Encouraging Preliminary Phase 1 Dose-Escalation Data for XTX101, a Tumor-Selective Anti-CTLA-4, and Reports Pipeline and Business Updates and Second Quarter 2022 Financial Results XTX101, tumor-selective anti-CTLA-4, has successfully reached dose levels exceeding the target dose with limited active (unmasked) molecule in the periphery in ongoing Phase 1 cli

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): July 25, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commiss

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): June 15, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commiss

Amended and Restated Employment Agreement, dated June 15, 2022, by and between the Registrant and Martin Huber, M.D.

Exhibit 10.1 AMENDED AND RESTATED EMPLOYMENT AGREEMENT THIS AMENDED AND RESTATED EMPLOYMENT AGREEMENT (the ?Agreement?), is made as of June 15, 2022 (the ?Effective Date?) by and between Xilio Therapeutics, Inc. (the ?Company?), and Martin Huber, M.D. (the ?Executive?) (together, the ?Parties?). RECITALS WHEREAS, the Company and the Executive are party to an Employment Agreement, dated as of Septe

Submission of Matters to a Vote of Security Holders

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): June 9, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commissi

Xilio Therapeutics Reports Pipeline and Business Highlights and First Quarter 2022 Financial Results Clinical programs for XTX202, a tumor-selective IL-2, and XTX101, a tumor-selective anti-CTLA-4, continue to advance with preliminary data anticipate

Exhibit 99.1 Xilio Therapeutics Reports Pipeline and Business Highlights and First Quarter 2022 Financial Results Clinical programs for XTX202, a tumor-selective IL-2, and XTX101, a tumor-selective anti-CTLA-4, continue to advance with preliminary data anticipated in 2022 On track with plans to submit IND for XTX301, a tumor-selective IL-12, in second half of 2022 Strong financial position with $1

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): May 12, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commissi

Loan and Security Agreement, dated as of November 21, 2019, as amended, by and between the Registrant and Pacific Western Bank

Exhibit 10.1 AKREVIA THERAPEUTICS INC. AKREVIA CONCERTO LLC LOAN AND SECURITY AGREEMENT ? ? This LOAN AND SECURITY AGREEMENT (the ?Agreement?) is entered into as of November 21, 2019, by and between PACIFIC WESTERN BANK, a California state chartered bank (?Bank?), and Akrevia Therapeutics Inc. and Akrevia Concerto LLC (individually and collectively referred to as ?Borrower?). RECITALS Borrower wis

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

2 This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 , as amended, including, without limitation, statements regarding plans, strategies, timelines and expectations for X

Exhibit 99.2 XILIO THERAPEUTICS (NASDAQ: XLO) HARNESSING THE IMMUNE SYSTEM TO IMPROVE THE LIVES OF PEOPLE WITH CANCER MAY 12, 2022 ? 2022 Xilio Therapeutics, Inc. 2 This presentation contains forward - looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 , as amended, including, without limitation, statements regarding plans, strategies, timelines and expec

definitive proxy statement

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A 1 tmb-20220426xdefa14a.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only

As filed with the Securities and Exchange Commission on March 1, 2022

As filed with the Securities and Exchange Commission on March 1, 2022 Registration No.

Financial Statements and Exhibits, Results of Operations and Financial Condition

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): March 1, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commiss

Xilio Therapeutics Reports Pipeline and Business Progress and Fourth Quarter and Full Year 2021 Financial Results Initial Phase 1 Data Readouts from Clinical Trials of XTX101 and XTX202 Anticipated in 2022 On Track with Plans to Submit IND for XTX301

Exhibit 99.1 ? Xilio Therapeutics Reports Pipeline and Business Progress and Fourth Quarter and Full Year 2021 Financial Results ? Initial Phase 1 Data Readouts from Clinical Trials of XTX101 and XTX202 Anticipated in 2022 ? On Track with Plans to Submit IND for XTX301 in Second Half of 2022 ? Continue to Anticipate Cash Runway into 2024 with $198.1 Million in Cash and Cash Equivalents at Year-End

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.

Exhibit 4.3

Exhibit 4.3 ? DESCRIPTION OF SECURITIES REGISTERED UNDER SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED The following description of the securities of Xilio Therapeutics, Inc. (?us,? ?our,? ?we? or the ?Company?) registered under Section 12 of the Securities Exchange Act of 1934, as amended (the ?Exchange Act?), is intended as a summary only and therefore is not a complete descripti

Filing Fee Table

Exhibit 107.1 Calculation of Filing Fee Tables Form S-8 (Form Type) Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1?Newly Registered Securities ? ? ? ? ? ? ? ? Security Type Security Class Title Fee Calculation Rule Amount Registered (1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Commo

Letter Agreement, dated September 30, 2021, by and between the Registrant and Salvatore Giovine

Exhibit 10.20 ? EMPLOYMENT AGREEMENT THIS EMPLOYMENT AGREEMENT (the ?Agreement?), is made as of September 30, 2021 by and between Xilio Therapeutics, Inc. (the ?Company?), and Salvatore Giovine (the ?Executive?) (together, the ?Parties?). RECITALS WHEREAS, the Company desires to continue to employ the Executive as its Chief Financial Officer; and WHEREAS, the Company and the Executive are party to

US98422T1007 / Xilio Therapeutics, Inc. / Bain Capital Life Sciences Fund II, L.P. - SC 13G/A NO.1 Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G (Rule 13d-102) Information to be Included in Statements Filed Pursuant to ? 240.

US98422T1007 / Xilio Therapeutics, Inc. / RA CAPITAL MANAGEMENT, L.P. - SC 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 (Amendment No. 1 )* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designat

US98422T1007 / Xilio Therapeutics, Inc. / Flynn James E Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): February 3, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Comm

Identification of the subsidiary which acquired the security being reported on by the parent holding company.

Exhibit 99.1 Identification of the subsidiary which acquired the security being reported on by the parent holding company. Takeda Pharmaceutical Company Limited?s beneficial ownership of the reported securities is comprised of 1,475,121 shares of Common Stock held by Takeda Ventures, Inc., which is a direct, wholly owned subsidiary of Takeda Pharmaceuticals U.S.A. Inc., which is a direct subsidiar

JOINT FILING AGREEMENT

Exhibit 99.2 JOINT FILING AGREEMENT The undersigned hereby agree that the Statement on Schedule 13G filed herewith (and any amendments thereto), relating to the Common Stock of Xilio Therapeutics, Inc., a Delaware corporation, is being filed jointly with the Securities and Exchange Commission pursuant to Rule 13d-1(c) under the Securities Exchange Act of 1934, as amended, on behalf of each of the

US98422T1007 / Xilio Therapeutics, Inc. / TAKEDA PHARMACEUTICAL CO LTD - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) December 31, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate th

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): January 4, 2022 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commi

Xilio Therapeutics Appoints Yuan Xu, Ph.D., to its Board of Directors

Exhibit 99.1 Xilio Therapeutics Appoints Yuan Xu, Ph.D., to its Board of Directors WALTHAM, Mass., January 6, 2022 ? Xilio Therapeutics, Inc. (Nasdaq: XLO), a biotechnology company developing tumor-selective immuno-oncology therapies for people living with cancer, today announced the appointment of Yuan Xu, Ph.D., to its board of directors. ?Yuan is an industry veteran who brings broad, strategic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

Table of Contents ? ? UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Xilio Therapeutics Reports Pipeline and Business Progress and Third Quarter 2021 Financial Results Anticipate First Patient Dosing in Phase 1/2 Clinical Trial for XTX202, a Tumor-Selective IL-2, in First Quarter of 2022 Advancing Phase 1/2 Clinical T

Exhibit 99.1 Xilio Therapeutics Reports Pipeline and Business Progress and Third Quarter 2021 Financial Results ? Anticipate First Patient Dosing in Phase 1/2 Clinical Trial for XTX202, a Tumor-Selective IL-2, in First Quarter of 2022 ? Advancing Phase 1/2 Clinical Trial for XTX101, a Tumor-Selective Anti-CTLA-4 ? Successfully Closed IPO in Fourth Quarter of 2021, Raising Approximately $130 Millio

Financial Statements and Exhibits, Results of Operations and Financial Condition

? UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K ? CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 ? Date of report (Date of earliest event reported): December 2, 2021 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) ? Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Comm

Joint Filing Agreement, dated November 5, 2021, by and among RiverVest Venture Fund IV, L.P., RiverVest Venture Partners IV, L.P., RiverVest Venture Partners IV, LLC, Niall O’Donnell, Ph.D, John McKearn, Ph.D and Jay Schmelter.

Exhibit A JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k) In accordance with Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the undersigned persons agree and consent to the joint filing on their behalf of the Statement on Schedule 13D, including any amendments thereto, in connection with shares of common stock of Xilio Therapeutics, Inc.

XLO / Xilio Therapeutics Inc / RiverVest Venture Fund IV, L.P. - SC 13D Activist Investment

SC 13D SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 XILIO THERAPEUTICS, INC.

XLO / Xilio Therapeutics Inc / Bain Capital Life Sciences Fund II, L.P. - SC 13G Passive Investment

SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13G (Rule 13d-102) Information to be Included in Statements Filed Pursuant to § 240.

XLO / Xilio Therapeutics Inc / RA CAPITAL MANAGEMENT, L.P. - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Xilio Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) October 22, 2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the

XLO / Xilio Therapeutics Inc / Atlas Venture Fund XI, L.P. - SCHEDULE FILED TO REPORT ACQUISITION OF BENEFICIAL OWNERSHIP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.)* XILIO THERAPEUTICS, Inc. (Name of Issuer) COMMON STOCK, $0.0001 PAR VALUE (Title of Class of Securities) 98422T100 (CUSIP Number) October 26, 2021 (Date of Event Which Requires Filing of This Statement) Check the appropriate box to designate the rule pursu

XLO / Xilio Therapeutics Inc / SV7 Impact Medicine Fund LP - SC 13D Activist Investment

SC 13D 1 d252571dsc13d.htm SC 13D SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. )* XILIO THERAPEUTICS, INC. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 98422T100 (CUSIP Number) James Costine SV Health Investors 71 Kingsway London, WC2B 6ST United Kingdom +44 20 7421 7081

JOINT FILING AGREEMENT

CUSIP NO. 98422T100 Exhibit 99.1 JOINT FILING AGREEMENT In accordance with Rule 16a-3(j) and Rule 13d-1(k)(1) and under the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of Forms 3, 4, 5 and Schedules 13D and 13G (including any and all amendments thereto) with respect to the Common Stock, par value $0.0001 per share, of Xilio Thera

XLO / Xilio Therapeutics Inc / Flynn James E Passive Investment

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No.

Amended and Restated Bylaws of the Registrant

Exhibit 3.2 AMENDED AND RESTATED BYLAWS OF XILIO THERAPEUTICS, INC. TABLE OF CONTENTS Page ARTICLE I STOCKHOLDERS 1 1.1 Place of Meetings 1 1.2 Annual Meeting 1 1.3 Special Meetings 1 1.4 Record Date for Stockholder Meetings 1 1.5 Notice of Meetings 2 1.6 Voting List 2 1.7 Quorum 2 1.8 Adjournments 3 1.9 Voting and Proxies 3 1.10 Action at Meeting 3 1.11 Nomination of Directors 4 1.12 Notice of Bu

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 26, 2021 Xilio Therapeutics, Inc. (Exact Name of Registrant as Specified in Charter) Delaware 001-40925 85-1623397 (State or Other Jurisdiction of Incorporation) (Commission F

Restated Certificate of Incorporation 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 October 26, 2021)

Exhibit 3.1 RESTATED CERTIFICATE OF INCORPORATION OF XILIO THERAPEUTICS, INC. Xilio Therapeutics, Inc., a corporation organized and existing under the General Corporation Law of the State of Delaware (the ?Corporation?), does hereby certify that the name of the Corporation is Xilio Therapeutics, Inc. and the original certificate of incorporation of the corporation was filed with the Secretary of S

As filed with the Securities and Exchange Commission on October 22, 2021

As filed with the Securities and Exchange Commission on October 22, 2021 Registration No.

7,353,000 Shares Common Stock

TABLE OF CONTENTS ?Filed Pursuant to Rule 424(b)(4)? ?Registration No. 333-259973? PROSPECTUS 7,353,000 Shares Common Stock ? We are offering 7,353,000 shares of our common stock. This is our initial public offering, and no public market currently exists for our common stock. The initial public offering price is $16.00 per share. Our common stock has been approved for listing on the Nasdaq Global

As filed with the Securities and Exchange Commission on October 19, 2021

? As filed with the Securities and Exchange Commission on October 19, 2021 Registration No.

Xilio Therapeutics, Inc. 828 Winter Street, Suite 300 Waltham, Massachusetts 02451 October 19, 2021

Xilio Therapeutics, Inc. 828 Winter Street, Suite 300 Waltham, Massachusetts 02451 October 19, 2021 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Re: Xilio Therapeutics, Inc. Registration Statement on Form S-1 File No. 333-259973 Request for Acceleration Ladies and Gentlemen: Pursuant to Rule 461 promulgated under the Se

[Signature page follows]

October 19, 2021 U.S. Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attention: Ada Sarmento Tim Buchmiller Re: Xilio Therapeutics, Inc. Registration Statement on Form S-1 (File No. 333-259973) Request for Acceleration Ladies and Gentlemen: Pursuant to Rule 460 of the General Rules and Regulations under the Securities Act of 1933, as am

Amended and Restated Certificate of Incorporation of the Registrant, as amended

Exhibit 3.1   AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF XILIO THERAPEUTICS, INC.   (Pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware)   Xilio Therapeutics, Inc., a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware (the “General Corporation Law”),   DOES HEREBY CERTIFY:

As filed with the Securities and Exchange Commission on October 18, 2021

S-1/A 1 tm2115750-12s1a.htm S-1/A TABLE OF CONTENTS As filed with the Securities and Exchange Commission on October 18, 2021 Registration No. 333-259973 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 AMENDMENT NO. 1 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 XILIO THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware (S

October 18, 2021

October 18, 2021 +1 617 526 6000 (t) +1 617 526 5000 (f) wilmerhale.com By Electronic Submission Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, DC 20549 Attention: Ada Sarmento Re: Xilio Therapeutics, Inc. Registration Statement on Form S-1 Filed October 1, 2021 File No. 333-259973 Ladies and Gentlemen: On behalf of Xilio Therapeutics, Inc. (the ?

2021 Employee Stock Purchase Plan

Exhibit 10.8 Xilio Therapeutics, Inc. 2021 EMPLOYEE STOCK PURCHASE PLAN The purpose of this 2021 Employee Stock Purchase Plan (this ?Plan?) is to provide eligible employees of Xilio Therapeutics, Inc. (the ?Company?) and certain of its subsidiaries with opportunities to purchase shares of the Company?s common stock, $0.0001 par value per share (the ?Common Stock?), commencing at such time and on s

Form of Non-Employee Director Stock Option Agreement under the 2021 Stock Incentive Plan

Exhibit 10.7 Form of Non-Employee Director Nonstatutory Stock Option Agreement Xilio Therapeutics, Inc. NONSTATUTORY STOCK OPTION AGREEMENT FOR NON-EMPLOYEE DIRECTOR Xilio Therapeutics, Inc. (the ?Company?) hereby grants the following nonstatutory stock option to the optionee named below pursuant to the Company?s 2021 Stock Incentive Plan (as amended through the date hereof, the ?Plan?). The terms

Form of Stock Option Agreement under the 2021 Stock Incentive Plan

EX-10.6 6 tm2115750d13ex10-6.htm EXHIBIT 10.6 Exhibit 10.6 Form of Stock Option Agreement for Employees and Consultants Xilio Therapeutics, Inc. STOCK OPTION AGREEMENT Xilio Therapeutics, Inc. (the “Company”) hereby grants the following stock option to the optionee named below pursuant to the Company’s 2021 Stock Incentive Plan (as amended through the date hereof, the “Plan”). The terms and condit

2021 Stock Incentive Plan

Exhibit 10.5 Xilio Therapeutics, Inc. 2021 STOCK INCENTIVE PLAN 1. Purpose The purpose of this 2021 Stock Incentive Plan (the ?Plan?) of Xilio Therapeutics, Inc., a Delaware corporation (the ?Company?), is to advance the interests of the Company?s stockholders by enhancing the Company?s ability to attract, retain and motivate persons who are expected to make important contributions to the Company

Form of Underwriting Agreement

Exhibit 1.1 [•] Shares XILIO THERAPEUTICS, INC. COMMON STOCK, $0.0001 PAR VALUE PER SHARE UNDERWRITING AGREEMENT [•], 2021 [•], 2021 Morgan Stanley & Co. LLC Cowen and Company, LLC Guggenheim Securities, LLC c/o Morgan Stanley & Co. LLC 1585 Broadway New York, NY 10036 c/o Cowen and Company, LLC 599 Lexington Avenue New York, NY 10022 c/o Guggenheim Securities, LLC 330 Madison Avenue New York, NY

Form 8-A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Xilio Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 85-1623397 (State of incorporation or organization) (I.R.S. Employer Identification No.) 828 Winter Street,

Service Agreement, dated June 11, 2020, as amended, by and between the Registrant and Daniel S. Lynch

Exhibit 10.19 EXECUTION VERSION SERVICE AGREEMENT THIS SERVICE AGREEMENT (this ?Agreement?), made this 11th day of June, 2020, is entered into by Xilio Therapeutics Inc., a Delaware corporation (the ?Company?), and Daniel S. Lynch (the ?Director?). INTRODUCTION The Company and the Director desire to establish the terms and conditions under which the Director will serve as the Chairman of the board

Subsidiaries of the Registrant

Exhibit 21.1 Subsidiaries of the Registrant Entity Jurisdiction of Incorporation Xilio Securities Corporation Xilio Therapeutics LLC Xilio Concerto LLC Xilio Development, Inc. Massachusetts Delaware Delaware Delaware

Amended and Restated Certificate of Incorporation of the Registrant

Exhibit 3.1 ? AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF XILIO THERAPEUTICS,?INC. ? (Pursuant to Sections 242 and 245 of the General Corporation Law of the State of Delaware) ? Xilio Therapeutics,?Inc., a corporation organized and existing under and by virtue of the provisions of the General Corporation Law of the State of Delaware (the ?General Corporation Law?), ? DOES HEREBY CERTIFY:

Bylaws of the Registrant

Exhibit 3.2 Bylaws of Xilio Therapeutics, Inc. (a Delaware corporation) Table of Contents Page ARTICLE I STOCKHOLDERS 1 1.1 Place of Meetings 1 1.2 Annual Meeting 1 1.3 Special Meetings 1 1.4 Notice of Meetings 1 1.5 Voting List 2 1.6 Quorum 2 1.7 Adjournments 2 1.8 Voting and Proxies 2 1.9 Action at Meeting 3 1.10 Conduct of Meetings 3 1.11 Action without Meeting 4 ARTICLE II DIRECTORS 5 2.1 Gene

Lease, dated as of August 26, 2019, as amended, by and between the Registrant and PPF off 828-830 Winter Street, LLC

Exhibit 10.14 828 WINTER STREET WALTHAM, MASSACHUSETTS LEASE SUMMARY SHEET Execution Date: August 26, 2019 Tenant: AKREVIA THERAPEUTICS INC., a Delaware corporation Tenant’s Mailing Address Prior to Occupancy: Akrevia Therapeutics Inc. 610 Main Street Cambridge, MA 02139 Attn: Joseph Farmer Landlord: PPF OFF 828-830 WINTER STREET, LLC, a Delaware limited liability company Building: 828 Winter Stre

Form of Restricted Stock Agreement under 2020 Stock Incentive Plan

Exhibit 10.4 Xilio Therapeutics, Inc. Restricted Stock Agreement Granted Under 2020 Stock Incentive Plan This Restricted Stock Agreement (the ?Agreement?) is made this [] day of [], 20[ ], between Xilio Therapeutics, Inc., a Delaware corporation (the ?Company?), and [] (the ?Participant?). For valuable consideration, receipt of which is acknowledged, the parties hereto agree as follows: 1.????????

Form of Stock Option Agreement under 2020 Stock Incentive Plan

EX-10.3 9 tm2115750d10ex10-3.htm EXHIBIT 10.3 Exhibit 10.3 Xilio Therapeutics, Inc. Stock Option Agreement Granted Under 2020 Stock Incentive Plan This Stock Option Agreement (this “Agreement”) is made between Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), and the Participant pursuant to the 2020 Stock Incentive Plan (the “Plan”). Notice of Grant I.             Participant Infor

Service Agreement, dated June 11, 2020, as amended, by and between the Registrant and Daniel S. Lynch

EX-10.19 21 tm2115750d10ex10-19.htm EXHIBIT 10.19 Exhibit 10.19 EXECUTION VERSION SERVICE AGREEMENT THIS SERVICE AGREEMENT (this “Agreement”), made this 11th day of June, 2020, is entered into by Xilio Therapeutics Inc., a Delaware corporation (the “Company”), and Daniel S. Lynch (the “Director”). INTRODUCTION The Company and the Director desire to establish the terms and conditions under which th

Power of Attorney (included on signature page)

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on October 1, 2021 Registration No.

2020 Stock Incentive Plan, as amended

Exhibit 10.2 2020 Stock Incentive Plan of Xilio Therapeutics, Inc. Table of Contents Page 1. Purpose 1 2. Eligibility 1 3. Administration and Delegation 1 (a) Administration by the Board 1 (b) Appointment of Committees 1 4. Stock Available for Awards 2 (a) Number of Shares 2 (b) Substitute Awards 2 5. Stock Options 2 (a) General 2 (b) Incentive Stock Options 2 (c) Exercise Price 3 (d) Duration of

Cross-License Agreement, dated as of December 16, 2020, by and between the Registrant and AskGene Pharma, Inc.

EX-10.11 13 tm2115750d10ex10-11.htm EXHIBIT 10.11   Exhibit 10.11   Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions.    CROSS-LICENSE AGREEMENT   This Cross-License Agreement (“Agreement”), effective as of December 16, 20

October 1, 2021

October 1, 2021 +1 617 526 6000 (t) +1 617 526 5000 (f) wilmerhale.com By Electronic Submission Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, DC 20549 Attention: Ada Sarmento Re: Xilio Therapeutics, Inc. Draft Registration Statement on Form S-1 Submitted September 14, 2021 CIK No. 0001840233 Ladies and Gentlemen: On behalf of Xilio Therapeutics,

Form of Restated Certificate of Incorporation of the Registrant (to be effective upon the closing of this offering)

Exhibit 3.3 RESTATED CERTIFICATE OF INCORPORATION OF XILIO THERAPEUTICS, INC. Xilio Therapeutics, Inc., a corporation organized and existing under the General Corporation Law of the State of Delaware (the ?Corporation?), does hereby certify that the name of the Corporation is Xilio Therapeutics, Inc. and the original certificate of incorporation of the corporation was filed with the Secretary of S

Amended and Restated Exclusive License Agreement, dated as of August 16, 2016, by and between the Registrant and City of Hope

Exhibit 10.12 EXECUTION COPY Certain identified information has been excluded from the exhibit because it is both (i) not material and (ii) is the type of information that the registrant treats as private or confidential. Double asterisks denote omissions. AMENDED AND RESTATED EXCLUSIVE LICENSE AGREEMENT THIS AMENDED AND RESTATED EXCLUSIVE LICENSE AGREEMENT (this ?Agreement?) is made and entered i

Separation Agreement, dated March 12, 2021, by and between the Registrant and Joseph Farmer

EX-10.18 20 tm2115750d10ex10-18.htm EXHIBIT 10.18   Exhibit 10.18   VIA ELECTRONIC MAIL   March 12, 2021   Joseph L. Farmer   Dear Joe:   As we discussed, your employment with Xilio Therapeutics, Inc. (f/k/a/ Akrevia Therapeutics, Inc., and hereinafter, the “Company”) will end effective March 12, 2021 (the “Separation Date”). As we also discussed, although you are electing to leave the Company, th

Specimen Stock Certificate evidencing the shares of common stock

Exhibit 4.1 ZQ|CERT#|COY|CLS|RGSTRY|ACCT#|TRANSTYPE|RUN#|TRANS# COMMON STOCK PAR VALUE $0.0001 COMMON STOCK SEE REVERSE FOR CERTAIN DEFINITIONS Certificate Number Shares . XILIO THERAPEUTICS, INC. INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE ZQ00000000 INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE FACSIMILE SIGNATURE TO COME FACSIMILE SIGNATURE TO COME President Secretary By AUTHORI

Letter Agreement, dated May 24, 2019, by and between the Registrant and Joseph Farmer

Exhibit 10.16 May 24, 2019 Joseph L. Farmer Re: Employment Agreement Dear Joe: On behalf of Akrevia Therapeutics Inc. (the “Company”), I am pleased to offer you the position as the Company’s Chief Operating Officer (“COO”). The terms of your employment are set forth below in this Employment Agreement (the “Agreement.) 1. Position. As the Company’s CBO/COO, you will report to the Company’s Chief Ex