The FDA has approved Keytruda (pembrolizumab), an anti-PD-1 (programmed death receptor-1) therapy, at a fixed dose of 200 mg every 3 weeks, for the treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) with disease progression on or after platinum-containing chemotherapy.
Under the FDA's accelerated approval regulations, this indication for pembrolizumab is approved based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. For HNSCC patients, PD-L1 testing is not needed prior to use of pembrolizumab.
The approval is based on data from the KEYNOTE-012 study, which included patients with recurrent or metastatic HNSCC who had disease progression on or after platinum-containing chemotherapy or following platinum-containing chemotherapy administered as part of induction, concurrent, or adjuvant therapy and ECOG performance status of zero or one. The data showed an objective response rate (ORR) of 16 percent (95% CI: 11, 22), complete response rate of 5 percent, with responses of 6 months or longer observed in 82 percent (n=23/28) of the responding patients. ORR and duration of response were similar regardless of human papillomavirus status.
KEYNOTE-012 was the first clinical study to investigate the role of a PD-1 inhibitor in patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy.
Pembrolizumab is a humanized monoclonal antibody that works by increasing the ability of the body's immune system to help detect and fight tumor cells. It blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes that may affect both tumor cells and healthy cells.