Merck Receives Accelerated Approval of the First FDA-Approved Anti-PD-1 Therapy

Merck announced on Sept. 4, 2014 that FDA approved KEYTRUDA (pembrolizumab) for the treatment of patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials.

KEYTRUDA is the first anti-PD-1 (programmed death receptor-1) therapy approved in the United States. For the recommended dose of 2 mg/kg every three weeks based on data in 89 patients, the overall response rate was 24% (95% CI: 15, 34), with one complete response and 20 partial responses (21/89). At the time of analysis, 86% (18/21) of patients with objective responses had ongoing responses with durations ranging from 1.4+ to 8.5+ months, including eight patients with ongoing responses of six months or longer. Fourteen percent (3/21) had progression of disease 2.8, 2.9, and 8.2 months after initial response.

KEYTRUDA is a humanized monoclonal antibody that works by increasing the ability of the body’s immune system to fight advanced melanoma. KEYTRUDA blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, and may affect both tumor cells and healthy cells. Merck is conducting ongoing Phase II and III clinical studies in advanced melanoma, which are designed to provide further confirmatory evidence for KEYTRUDA in this indication. Merck plans to make KEYTRUDA available within one week from Sept. 4.