ST316 β-Catenin/BCL9 Antagonist Reaches 46.7% ORR With 2L FOLFIRI/Bev in MSS mCRC

ST316 is a first-in-class IV peptide antagonist of the β-catenin–BCL9/9L interaction, designed to suppress oncogenic Wnt/β-catenin transcription while sparing physiologic Wnt signaling. In the ongoing Phase 1/2 ST316-101 study (NCT05848739), Phase 2 expansion in evaluable second-line metastatic CRC patients (n=15; 100% MSS; 73% RAS-mutant) treated with ST316 plus FOLFIRI/bevacizumab produced confirmed ORR 46.7% and DCR 93.4%. Common AEs included nausea, fatigue, ALT/AST elevations, and neutropenia, with grade 3 transaminitis and neutropenia; the ORR is well above historical second-line FOLFIRI/bevacizumab expectations around ~11% in EAGLE.