CD274 and head and neck squamous cell carcinoma: At final analysis, favorable OS results were observed for pembrolizumab monotherapy in the programmed death-ligand 1 (PD-L1) combined positive score (CPS) ≥1 population (median OS 12.3 months versus 10.3 months; hazard ratio [HR] 0.74 [95% CI 0.61–0.90]) and for pembrolizumab plus chemotherapy (median OS 13.0 months versus 10.7 months; HR 0.72 [95% CI 0.60–0.87]) in the overall R/M HNSCC population compared to the EXTREME regimen.