Survival benefit and biomarker of PD-1 inhibitor combination therapy in first-line of advanced biliary tract cancer: A retrospective study.

First-line anti-PD-1 combination therapy was superior to chemotherapy, and triple therapy significantly improved survival. Peripheral blood immune-inflammation score, FOXP3/CD8 ratio, and PLUS have potential as biomarkers for predicting the efficacy of first-line anti-PD-1 therapy in advanced BTC.