The European Commission subsequently approved nivolumab in 2017 for the treatment of the same patient population, followed by the approval of pembrolizumab as a type of monotherapy soon after for the treatment of recurrent or metastatic HNSCC in adults whose tumors express PD-L1 with a tumor proportion score of ≥50% and who have progressed on or after platinum-containing chemotherapy. This evidence concerns the gene CD274 and neoplasm.