Xilio Therapeutics to Present New Preclinical Data for its Masked T Cell Engager Program Targeting CLDN18.2 at the American Association for Cancer Research (AACR) Annual Meeting

WALTHAM, Mass., March 17, 2026 — Xilio Therapeutics, Inc. (Nasdaq: XLO), a clinical-stage biotechnology company discovering and developing masked immuno-oncology therapies for people living with cancer, today announced an upcoming poster presentation at the American Association for Cancer Research (AACR) Annual Meeting, taking place from April 17-22, 2026 at the San Diego Convention Center in San Diego, California.

Poster presentation details, as follows:

Title: Discovery and Optimization of XTX601, a Masked Claudin 18.2-Targeting T Cell Engager Session Category: Immunology Session Title: T Cell Engagers 1 Session Date and Time: Monday, Apr. 20, 2026, from 9:00 a.m. to 12:00 p.m. PST Location: Poster Section 10 Poster Board: 11 Abstract Number: 1619

About Xilio Therapeutics

Xilio Therapeutics is a clinical-stage biotechnology company discovering and developing masked immuno-oncology (I-O) therapies with the goal of significantly improving outcomes for people living with cancer without the systemic side effects of current I-O treatments. Leveraging our clinically-validated masking technology and capabilities, Xilio is developing I-O therapies designed to selectively activate within the tumor microenvironment to achieve durable efficacy without the severe side effects associated with systemically active I-O agents. Learn more by visiting www.xiliotx.com and follow us on LinkedIn.

Investor Contact

Alex Lobo, Precision AQ [email protected]

Media Contact

Josie Butler, 1AB [email protected]