A phase 3 randomized, double-blind, placebo-controlled study of durvalumab in combination with gemcitabine plus cisplatin (GemCis) in patients (pts) with advanced biliary tract cancer (BTC): TOPAZ-1.

378 Background: BTC is a rare, heterogenous cancer with poor prognosis. Reports on immunogenic features of BTC suggest checkpoint inhibition may result in antitumor immune responses, and limited clinical activity has been seen with single agents in advanced settings. Durvalumab (PD-L1 inhibitor) + GemCis showed promising antitumor activity in advanced BTC in a phase 2 study. TOPAZ-1 (NCT03875235) is the first global phase 3 study to evaluate...