FDA Approval Summary: Pembrolizumab for the Treatment of Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma with Disease Progression on or After Platinum-Containing Chemotherapy

On August 5, 2016, the U.S. Food and Drug Administration granted accelerated approval to pembrolizumab (KEYTRUDA injection, Merck Sharp & Dohme Corp., Kenilworth, NJ) for treatment of patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) with disease progression on or after platinum-containing chemotherapy. Approval was based on the objective response rate (ORR) and duration of response (DoR) in a cohort of patients in a nonrandomized multi-cohort trial (KEYNOTE-012) that included 174 patients with recurrent or metastatic HNSCC who had disease progression on or after platinum-containing chemotherapy. Patients received either intravenous pembrolizumab 10 mg/kg every 2 weeks or 200 mg every 3 weeks. ORR was determined by independent review according to Response Evaluation Criteria in Solid Tumors 1.1. ORR was 16% (95% confidence interval 11, 22) with a complete response rate of 5%. DoR ranged from 2.4+ months to 27.7+ months. Twenty-three of 28 responding patients (82%) had response durations of ≥6 months. Safety was evaluated in 192 patients with HNSCC receiving at least one dose of pembrolizumab. Frequent (≥2%) serious adverse reactions were pneumonia, dyspnea, confusional state, vomiting, pleural effusion, and respiratory failure. Clinically significant immune-mediated adverse reactions included pneumonitis, colitis, hepatitis, adrenal insufficiency, diabetes mellitus, skin toxicity, myositis, and thyroid disorders. The benefit-risk profile of pembrolizumab was considered acceptable in this patient population. As a condition of accelerated approval, Merck is required to conduct a confirmatory trial; this trial, KEYNOTE-040, is ongoing.

Implications for practice: This accelerated approval expands the U.S. Food and Drug Administration-approved indications for pembrolizumab, providing health care providers with new information regarding pembrolizumab 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. Pembrolizumab is the first drug to receive approval for treatment of patients with HNSCC since cetuximab was approved for this indication in 2006.