Xilio Therapeutics(US:XLO)2025-11-10 22:32Summary of Xilio Therapeutics Conference Call Company Overview - Company: Xilio Therapeutics (NasdaqGS:XLO) - Focus: Development of novel masked biologics using proprietary protein engineering technology - Key Products: Velastigard (anti-CTLA-4), efarindodekin alfa (IL-12), XTX501 (PD-1/IL-2) Industry Context - Industry: Oncology, specifically focusing on immunotherapy for colorectal cancer - Target Condition: Microsatellite stable colorectal cancer (MSSCRC), which constitutes 95% of all colon cancers Key Data Updates - SITC Conference: Presented new clinical data for Velastigard in combination with Tislelizumab for MSSCRC - Clinical Data: - Velastigard demonstrated a 26% overall response rate in late-line metastatic MSSCRC without liver metastases, compared to a 2% response rate for Tislelizumab as monotherapy [8][9][10] - In a biomarker-defined population with high plasma tumor mutational burden (TMB), the overall response rate was 40% [14][15] Biomarker Insights - Plasma TMB: - Approximately 55% of MSSCRC patients have high plasma TMB (greater than 10 mutations per megabase) [12][15] - High plasma TMB correlates with better response rates to Velastigard and Tislelizumab combination therapy [12][14] - Plasma-based TMB assays are more sensitive and provide a comprehensive assessment compared to traditional tissue-based assays [11][19] Safety Profile - Safety Data: - Velastigard showed a 7% incidence of colitis, significantly lower than traditional anti-CTLA-4 therapies [16][17] - Discontinuation rate for the combination therapy was only 5%, indicating a favorable safety profile [17] Future Development Plans - Partnerships: Actively seeking partnerships to develop Velastigard in combination with PD-1, PD-L1, or newer PD-1 bispecifics [43][44] - Regulatory Path: Plans to assess the regulatory pathway for future development using plasma TMB as a predictive biomarker [43][44] - Upcoming Milestones: Additional phase two data for Velastigard expected in the first half of 2026 [47] Additional Clinical Programs - Efarindodekin alfa: Phase one data showed deep monotherapy responses and a well-tolerated safety profile [45] - Masked T-cell Engagers: Preclinical data demonstrated broad applicability and potential for reduced systemic toxicity [46] Conclusion - Xilio Therapeutics is positioned to leverage its innovative masking technology to address significant unmet medical needs in oncology, particularly in MSSCRC, with promising clinical data supporting the efficacy and safety of its lead product, Velastigard. The identification of plasma TMB as a predictive biomarker enhances the potential for targeted therapies in this patient population.