A Phase III, Randomized, Open-label Study to Evaluate Pembrolizumab as Neoadjuvant Therapy and in Combination With Standard of Care as Adjuvant Therapy for Stage III-IVA Resectable Locoregionally Advanced Head and Neck Squamous Cell Carcinoma (LA HNSCC)

This is a randomized, active-controlled, open-label study of pembrolizumab given prior to surgery and pembrolizumab in combination with standard of care radiotherapy (with or without cisplatin), as post-surgical therapy in treatment naïve participants with newly diagnosed Stage III/IVA, resectable, locoregionally advanced, head and neck squamous cell carcinoma (LA-HNSCC). Efficacy outcomes will be stratified by programmed cell death ligand 1 (PD-L1) combined positive score (CPS) status. The primary hypothesis is that pembrolizumab given before surgery and after surgery in combination with radiotherapy (with or without cisplatin) improves event-free survival compared to radiotherapy (with or without cisplatin) given after surgery alone.