Arkenau HT, et al. - Researchers attempted to evaluate the safety and efficacy of ramucirumab, an IgG1 vascular endothelial growth factor receptor 2 (VEGFR-2) antagonist, with pembrolizumab, an IgG4 programmed death 1 (PD-1) antagonist, in biomarker-unselected patients with previously treated advanced or metastatic biliary tract cancer (BTC). Study participants were patients who had previously treated advanced or metastatic adenocarcinoma of the gallbladder, intrahepatic and extrahepatic bile ducts, or ampulla of Vater. Safety and tolerability of the combination was the primary endpoint. Objective response rate, progression-free survival, and overall survival were the included secondary endpoints. In patients with biomarker-unselected progressive BTC, ramucirumab-pembrolizumab displayed limited clinical activity with infrequent grade 3–4 treatment-related adverse events (TRAEs), with hypertension being the most common grade 3 event.