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 tumoractivated, 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 colorectal cancer (MSS CRC) for vilastobart in combination with atezolizumab in the fourth quarter of 2024 Expect to ...

Combination of vilastobart and atezolizumab demonstrated encouraging early evidence of anti-tumor activity, including unconfirmed partial responses observed in two patients with difficult-to-treat, immunologically “cold” tumors Complete resolution of a metastatic liver lesion observed in a patient with microsatellite stable colorectal cancer (MSS CRC) Safety data indicated combination of vilastobart and atezolizumab was generally well-tolerated and support the potential of vilastobart to be a differentiated ...

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 colorectal cancer (MSS CRC) for vilastobart in combination with atezolizumab in the fourth quarter of 2024 Expect to report Phase 1 data for XTX301, a tumor-activated IL-12, in the fourth quarter of 2024 WALTHAM, Mass., Nov. 07, ...

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 | --- | --- | |----------------------------------------------------------------------------------------------------------|-------------------------------------------------- ...

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-activated IL-12, in patients with advanced solid tumors; Phase 1A monotherapy dose escalation ongoing with no dose-l ...

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-activated IL-12, in patients with advanced solid tumors; Phase 1A monotherapy dose escalation ongoing with no dose-limiting toxicities observed to date Expect to report clinical data for XTX101 and XTX301 in the fourth quarter of ...

(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 Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q 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 Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 85-1623397 (St ...

Exhibit 99.1 Xilio Therapeutics Announces Pipeline and Business Updates and First Quarter 2024 Financial Results WALTHAM, Mass., May 14, 2024 -- 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 pipeline progress and business updates and reported financial results for the first quarter ended March 31, 2024. Plan to report clinical data for XTX101 and XTX301, a tum ...

Table of Contents ☐ 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 THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) (State of Other Jurisdiction of incorporation or Organization) (I.R.S. Employer Identification No.) 828 Winter Street, Suite 300, Waltham, MA 02451 (Address of principal executive offices) (Zip code) Delaware 85-1623397 UNITED STATES SE ...

Exhibit 99.1 XTX101 is an investigational tumor-activated, Fc-enhanced, high affinity binding anti-CTLA-4 designed to block CTLA-4 and deplete regulatory T cells when activated (unmasked) in the tumor microenvironment (TME). XTX101 is currently being evaluated in combination with atezolizumab in an ongoing Phase 1 clinical trial in patients with advanced solid tumors. Xilio Therapeutics Announces Pipeline and Business Updates and Fourth Quarter and Full Year 2023 Financial Results Anticipates cash runway in ...