Efficacy and safety of immune checkpoint inhibitors in recurrent or metastatic head and neck squamous cell carcinoma: A systematic review and meta-analysis of randomized clinical trials.

Anti-PD1/PDL1 monotherapy could improve OS for R/M HNSCC with significant lower incidence of TRAEs compared with SOC. PD1/PDL1 inhibitors plus CTLA4 inhibitors showed no more benefit compared with both SOC and ICIs monotherapy, but the incidence of Grades 3-5 TRAEs was significant higher compared with ICIs monotherapy.