RetroSpective cohort stUdy of PD-L1 expression in REcurrent and/or MEtastatic squamous cell carcinoma of the head and neck (SUPREME-HN)

Pai, ; Cohen, ; E., E.; Lin, ; Fountzilas, ; Kim, ; E., S.; Mehlhorn, ; Baste, ; Clayburgh, ; Lipworth, ; Resteghini, C; Shara, ; Fujii, ; Zhang, ; Stokes, ; Lawrence, ; Khaliq, ; Melillo, ; Shire,