An open label PhaseII randomized trial of BNT113 incombination with pembrolizumab versuspembrolizumab monotherapy as a first line therapy in patients withunresectable recurrent, or metastatic Head and Neck Squamous CellCarcinoma (HNSCC) which is positive for human papilloma virus 16 (HPV16+)and expresses PD-L1 (AHEAD-MERIT)