EGFR and head and neck squamous cell carcinoma: The combination of pembrolizumab plus the chimeric mouse IgG1 anti-epidermal growth factor receptor (EGFR) mAb, cetuximab, was investigated in a phase II trial in patients with platinum-resistant or -ineligible R/M HNSCC; at 6 months, the ORR was 45% (95% CI 28–62) with serious treatment-related adverse events noted in 5 of 33 (15%) participants [43].