Merck & Co. Receives FDA Approval for Immunotherapy PembrolizumabBy
Merck & Co. has received approval from the US Food and Drug Administration (FDA) for Keytruda (pembrolizumab) for treating advanced or unresectable melanoma, making it, the first anti-PD-1 (programmed death receptor-1) therapy approved in the United States.
Keytruda is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2. By binding to the PD-1 receptor and blocking the interaction with the receptor ligands, Keytruda releases the PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response.
Keytruda is intended for use following treatment with ipilimumab, a type of immunotherapy. For melanoma patients whose tumors express a gene mutation called BRAF V600, Keytruda is intended for use after treatment with ipilimumab and a BRAF inhibitor, a therapy that blocks activity of BRAF gene mutations.
Keytruda is the sixth new melanoma treatment approved since 2011. The five prior FDA approvals for melanoma include: Bristol-Myers Squibb’s Yervoy (ipilimumab (2011), Merck & Co,’s peginterferon alfa-2b (2011), Roche’s Zelbora (vemurafenib) (2011), GlaxoSmithKline’s (GSK) Tafinlar (dabrafenib) (2013), and GSK’s Mekinist (trametinib) (2013). at a dose of 2 mg/kg every three weeks for the treatment of patients with unresectable or metastatic melanoma and disease progression following ipilimumab and, if BRAF V600 mutation positive, a BRAF inhibitor. This indication is approved under accelerated approval based on tumor response rate and durability of response. An improvement in survival or disease-related symptoms has not yet been established. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials.
Merck is planning Phase II and III clinical studies in advanced melanoma, which are designed to provide further confirmatory evidence for this indication; the drug is expected to available within Sept. 11, within one week from the FDA’s approval on September 4, 2014.The drug had received breakthrough therapy status and accelerated approval by the FDA.
See related story, “Immunotherapies: The Next Wave in Biologic-Based Oncology Drugs”