Xilio Therapeutics Presents Promising Initial Data for Vilastobart (XTX101) in Combination with Atezolizumab at ASCO GI 2025

Xilio Therapeutics shared encouraging initial Phase 2 data for its investigational anti-CTLA-4 monoclonal antibody, vilastobart (XTX101), in combination with atezolizumab (Tecentriq®). The trial evaluated the combination in metastatic microsatellite stable colorectal cancer (MSS CRC), traditionally resistant to immunotherapy. Highlights include a 27% objective response rate (ORR) in patients without liver metastases, with confirmed partial responses and significant biomarker reductions. 

The combination therapy was well-tolerated, showing low immune-related adverse events (irAEs) and promising safety, underscoring its potential for broader tumor applications. Xilio plans further updates mid-2025 and seeks partnerships for expanded development.