An Open-label Phase II/III Randomized Trial of BNT113 in Combination With Pembrolizumab Versus Pembrolizumab Monotherapy as a First Line Therapy in Patients With Unresectable Recurrent, or Metastatic Head and Neck Squamous Cell Carcinoma (HNSCC) Which is Positive for Human Papilloma Virus 16 (HPV16+) and Expresses PD-L1 | Arctuva