Pembrolizumab for the treatment of head and neck squamous cell cancer.

: Groundbreaking progress in cancer immunotherapy in the recent years has revolutionized the field of oncology with unprecedented survival rates in multiple cancer types. Head and neck cancers comprise the sixth most common cancer type in the United States with estimated 14,620 deaths in 2019. Two checkpoint inhibitors, e.g. antibodies against programmed cell death protein 1 (PD-1), are currently FDA approved for second-line therapy of recurrent and/or metastatic head and neck squamous cell carcinomas (HNSCC). Pembrolizumab is one of the two approved anti-PD-1 antibodies and under active investigation of its role in managing HNSCCs. : This review provides an in-depth discussion of pembrolizumab's structural features, pharmacokinetics, pharmacodynamics, efficacy data, toxicity profile, ongoing studies, and competing agents including the standard of care options in the context of treating HNSCCs. : Immune checkpoint inhibitor therapy is already an integral part of HNSCC management, especially in the recurrent and/or metastatic stage, and is preferable to conventional cytotoxic therapies due to a generally more favorable toxicity profile. Pembrolizumab's role in treating HNSCC is highly anticipated to expand over to other contexts such as definitive combination therapy and neoadjuvant therapy for locally advanced HNSCC.