Cemiplimab (PD-1) + cisplatin/docetaxel induction delivers 83% ORR in stage IV LA SCCHN (Phase 1)

Cemiplimab is an anti–PD-1 checkpoint inhibitor combined here with induction cisplatin + docetaxel (TP) ahead of definitive standard-of-care surgery and/or concurrent chemoradiation, followed by adjuvant cemiplimab, in a Phase 1, non-randomized 3+3 feasibility study (NCT05376553) in previously untreated stage IV locally advanced SCCHN (n=24; 15 oropharynx [HPV+ 9], 3 oral cavity, 3 hypopharynx, 2 larynx, 1 nasopharynx). ORR was 83.33% (CR 58.33% [14/24], PR 16.67% [4/24]) with 6/24 progressions; 16/24 (67%) were alive in remission at a median 21-month follow-up, and relapse rate was reported as 18.18%; in the oral cavity subset, 3/5 achieved pathologic CR after resection. No dose-limiting toxicities (DLTs) attributable to cemiplimab were seen in cycle 1; interpretation is constrained by small n, mixed definitive local therapies, and the fact that multiple prior Phase 3 “add PD-1/PD-L1 to CRT” strategies have not clearly improved event-level endpoints versus CRT alone in unselected LA HNSCC populations (e.g., KEYNOTE-412).