Rilvegostomig (PD-1×TIGIT bispecific) + gem/cis posts 16.8-mo OS in 1L advanced BTC

Rilvegostomig (R) is a monovalent, Fc-reduced PD-1×TIGIT bispecific antibody designed to synchronously block PD-1 and TIGIT on immune effector cells; it was combined with gemcitabine/cisplatin in the global Phase 2 GEMINI-Hepatobiliary substudy 2 cohort A (NCT05775159) in previously untreated unresectable/metastatic biliary tract cancer with ECOG 0–1 (n=30; n=29 response-evaluable). At the Oct 24, 2025 cutoff, investigator-assessed confirmed ORR was 31% with DCR 93.1%, median PFS 8.2 months (6-mo PFS 73.0%), and median OS 16.8 months with 18-mo OS 44.8%—numerically above the current 1L gem/cis + PD-(L)1 benchmarks (e.g., durvalumab + gem/cis mOS 12.9 months in TOPAZ-1; pembrolizumab + gem/cis mOS 12.7 months in KEYNOTE-966), though this is a small, single-arm dataset. Toxicity looked largely chemo-driven (anemia 53.3%, neutrophils decreased 50.0%, platelets decreased 43.3%); grade ≥3 R-related AEs were 16.7%, R discontinuation occurred in 3.3% (hepatic function abnormal), and treatment-related deaths were 0%.