Merck & Co. reports that the US Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to Keytruda  (pembrolizumab), the company's anti-PD-1 therapy, for the treatment of patients with epidermal growth factor receptor mutation-negative and anaplastic lymphoma kinase rearrangement-negative non-small cell lung cancer whose disease has progressed on or following platinum-based chemotherapy. This is the second Breakthrough Therapy Designation granted for Keytruda; it was previously granted breakthrough status for advanced melanoma.

The FDA's Breakthrough Therapy Designation is intended to expedite the development and review of a candidate that is planned for use, alone, or in combination, to treat a serious or life-threatening disease or condition when preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints. 

Keytruda received FDA approval in September 2014 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.

Keytruda is being studied across more than 30 types of cancers, as a monotherapy and in combination. In advanced lung cancer, Merck is advancing a clinical program investigating the use of Keytruda as a monotherapy and in combination across lines of therapy and histology, including exploring different tumor characteristics, such as PD-L1 expression as predictors of responsiveness. The company has two ongoing Phase II and III studies in advanced lung cancer, and an additional Phase III study is planned to begin in the fourth quarter of 2014.

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, the drug releases the PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response.

Source: Merck & Co.