Xilio Therapeutics' Phase 2 Data Shows Promising Response Rates

Xilio Therapeutics reports a 26% response rate in its Phase 2 trial for vilastobart combined with atezolizumab in resistant colorectal cancer patients, revealing significant potential despite some limitations.

Date: 31-05-2025

AI Rating: 6

Overview of Clinical Trial Results

Xilio Therapeutics has shared positive findings from its Phase 2 clinical trial for vilastobart, an investigational therapy targeting metastatic microsatellite stable colorectal cancer (MSS CRC). A preliminary objective response rate (ORR) of 26% was observed in heavily pre-treated patients, suggesting meaningful anti-tumor activity. The responses were characterized as deep and durable, lasting up to 37 weeks, and were associated with substantial decreases in tumor biomarkers and clinical symptom improvements.

Safety Profile

The combination of vilastobart with atezolizumab demonstrated a favorable safety profile with a low incidence of immune-related adverse events. Importantly, only 7% reported colitis, indicating that the treatment may have lower toxicity compared to other current alternatives.

Market Implications

These trial results were presented at the 2025 ASCO Annual Meeting, possibly enhancing the visibility and credibility of Xilio's research efforts. The favorable safety profile combined with preliminary positive response rates positions vilastobart as a potential player in a market with significant unmet needs. However, skepticism remains concerning the modest response rate, particularly given the heavily pre-treated nature of the patient population.

Long-term Development Outlook

Xilio's future prospects hinge on the successful development of vilastobart and building partnerships to advance this therapy. The company plans to increase patient enrollment and study higher dosage levels in upcoming trials. The company's ability to secure additional funding and navigate the clinical landscape will be crucial for its operational sustainability.

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