Unleashing the Potential of Immuno-Oncology Therapies June 5, 2025 © 2025 Xilio Therapeutics, Inc. 1 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: development timelines and anticipated milestones for Xilio's programs; the receipt of future contingent payments under Xilio's coll ...

WALTHAM, Mass., June 10, 2025 (GLOBE NEWSWIRE) -- 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 appointment of Akintunde (Tunde) Bello, Ph.D., to the company’s board of directors. “Tunde is an accomplished leader with a strong track record of successfully developing novel therapies across a broad range of therapeutic areas, including several important cance ...

Core Insights - Xilio Therapeutics announced a preliminary objective response rate (ORR) of 26% in heavily pre-treated patients with metastatic microsatellite stable colorectal cancer (MSS CRC) without liver metastases, demonstrating deep and durable responses lasting up to 37 weeks [1][4][10] - The combination therapy of vilastobart and atezolizumab showed a differentiated safety profile with a low incidence of immune-related adverse events, particularly colitis [2][7][11] - The ongoing Phase 2 trial is evaluating vilastobart in combination with atezolizumab, with plans to expand the study to include a higher dose level [9][13] Patient Data - As of May 12, 2025, 44 patients with metastatic MSS CRC were treated with vilastobart at 100 mg every six weeks and atezolizumab at 1200 mg every three weeks, with a median age of 55 years [3][5] - 80% of patients had previously received three or more lines of anti-cancer therapy, indicating a heavily pre-treated population [3] Anti-Tumor Activity - The preliminary ORR of 26% included seven partial responses, with six confirmed responses, and substantial decreases in tumor biomarkers such as circulating tumor DNA [4][10] - In patients without liver metastases, responses were deep and durable, with reductions in target lesions of up to 71% from baseline [10] Safety Profile - The combination therapy exhibited a low incidence of immune-mediated adverse events, with only 7% of patients experiencing colitis [7][11] - Common treatment-related adverse events included fatigue (30%), infusion-related reactions (23%), and diarrhea (18%) [11] Future Development Plans - Xilio is enrolling a cohort of patients at a higher dose level of 150 mg Q6W for vilastobart in the ongoing Phase 2 trial, with additional data expected in the first half of 2026 [9][12] - The company is seeking partnership opportunities to accelerate the development of the vilastobart program [12]

Core Insights - Xilio Therapeutics, Inc. is set to present updated data from its Phase 2 clinical trial of vilastobart, an anti-CTLA-4 therapy, in combination with atezolizumab for metastatic microsatellite stable colorectal cancer at the 2025 ASCO Annual Meeting [1] - The presentation will take place on May 31, 2025, during a poster session focused on gastrointestinal cancer [2] Company Overview - Xilio Therapeutics is a clinical-stage biotechnology company focused on developing tumor-activated immuno-oncology therapies aimed at improving cancer treatment outcomes while minimizing systemic side effects [3] - The company utilizes a proprietary platform to create novel tumor-activated immuno-oncology molecules that enhance localized anti-tumor activity within the tumor microenvironment [3] Clinical Trial Details - Vilastobart is designed to block CTLA-4 and deplete regulatory T cells when activated in the tumor microenvironment [2] - In 2023, Xilio entered a collaboration with Roche to co-fund a clinical trial evaluating vilastobart in combination with atezolizumab in a multi-center, open-label Phase 1/2 trial [2] - The ongoing trials include a Phase 1C dose escalation for advanced solid tumors and a Phase 2 trial for metastatic microsatellite stable colorectal cancer, with and without liver metastases [2]