We performed an integrated biomarker evaluation in pembrolizumab-treated patients with R/M HNSCC enrolled in KEYNOTE-012 or KEYNOTE-055. The relationship between biomarkers and HPV status was explored.We evaluated PD-L1 (combined positive score [CPS]), TMB, T-cell-inflamed gene expression profile (TcellTwo hundred and fifty-seven patients (KEYNOTE-012, n = 106; KEYNOTE-055, n = 151) had TMB data available; of these, 254 had PD-L1 and 236 had TcellTMB and the inflammatory biomarkers PD-L1 and Tcell