Durvalumab (PD-L1) + GemCis Extends 4-Year Survival in 1L Advanced Biliary Tract Cancer

Durvalumab is an anti–PD-L1 monoclonal antibody added to gemcitabine/cisplatin (GemCis) in the global, double-blind Phase 3 TOPAZ-1 first-line aBTC trial (NCT03875235). In this 4-year post hoc update (data cutoff February 28, 2025), durvalumab+GemCis improved median OS to 13.0 vs 11.4 months with placebo+GemCis (HR 0.75, 95% CI 0.64–0.88) and increased 48-month OS to 11.8% vs 4.3% (n=341 vs 344). Safety remained comparable, with treatment-related serious AEs in 15.4% vs 17.3% and discontinuations due to AEs in 6.2% vs 5.3%—and vs historical chemo-only SOC (ABC-02 CisGem) with mOS ≈11.7 months, this looks like a modest median gain but a clearer “tail” of long-term survivors.