Safety evaluation of pembrolizumab for treating recurrent head and neck squamous cell carcinoma.

Superior OS for pembrolizumab as first-line monotherapy was demonstrated in the CPS ≥ 20 and CPS ≥ 1 populations, with favorable toxicity profile when compared to the EXTREME regimen. Patient selection through adequate PD-L1 scoring is thus essential in order to limit upfront exposure to combination chemotherapy. Further trials are currently investigating the safety of PD-L1 inhibitors, alone or in combination with anti-CTLA-4 therapies.