Abstract LB-258: Efficacy of first-line (1L) pembrolizumab by PD-L1 combined positive score <1, 1-19, and ≥20 in recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC): KEYNOTE-048 subgroup analysis

Introduction: In the phase 3 KEYNOTE-048 trial (NCT02358031) in R/M HNSCC, first-line pembrolizumab (P) monotherapy vs EXTREME (E; chemotherapy [C] + cetuximab) improved overall survival (OS) in PD-L1 combined positive score (CPS) ≥20 and CPS ≥1 populations and led to noninferior OS in the total population with favorable safety; first-line P+C vs E had superior OS in CPS ≥20, CPS ≥1, and total populations with comparable safety. Outcomes in CPS Citation Format: Barbara Burtness, Danny Rischin, Richard Greil, Denis Soulieres, Makoto Tahara, Gilberto de Castro, Amanda Psyrri, Neus Baste, Prakash Neupane, Ase Bratland, Thorsten Fuereder, Brett G. Hughes, Ricard Mesia, Nuttapong Ngamphaiboon, Tamara Rordorf, Wan Zamaniah Wan Ishak, Joy Ge, Ramona Swaby, Burak Gumuscu, Kevin Harrington. Efficacy of first-line (1L) pembrolizumab by PD-L1 combined positive score