CD274 and neoplasm: The subsequent KEYNOTE-158, a nonrandomized, open-label, phase II trial, went on to evaluate pembrolizumab monotherapy in patients with advanced BTC, regardless of PD-L1 status, but was unable to replicate the same anti-tumor activity, instead reporting an ORR of 5.8%, a median PFS of 2.0 months, and a median OS of 7.4 months [46].