CD274 and triple-negative breast carcinoma: In the phase 3 KEYNOTE-119 trial, pembrolizumab monotherapy did not significantly improve overall survival compared to single-agent chemotherapy in patients with previously treated metastatic triple-negative breast cancer, including in subgroups defined by PD-L1 expression (CPS ≥1 or CPS ≥10), despite a numerical trend favoring pembrolizumab in the CPS ≥10 subgroup (HR 0.78, p=0.057) (23).