FDA grants Breakthrough Therapy designation to MK-5172/MK-8742 for chronic HCV infection

Merck (NYSE:MRK), known as MSD outside the United States and Canada, announced today that the U.S. Food and Drug Administration (FDA) has granted MK-5172/MK-8742 Breakthrough Therapy designation for treatment of chronic hepatitis C virus infection. MK-5172/MK-8742 is an all-oral combination regimen consisting of MK-5172, an investigational HCV NS3/4A protease inhibitor, and MK-8742, an investigational HCV NS5A replication complex inhibitor. Interim data from an ongoing Phase IIB clinical trial evaluating MK-5172/MK-8742 in genotype 1 infected patients (C-WORTHY Study) is scheduled to be presented at the 64^th American Association for the Study of Liver Disease Annual Meeting, Washington D.C., Nov. 1-5.

"The designation of MK-5172/MK-8742 as a Breakthrough Therapy for chronic hepatitis C is an important milestone for Merck," said Dr. Roger M. Perlmutter, president, Merck Research Laboratories. "There remains significant unmet medical need in hepatitis C, and we are looking forward to working with the FDA to advance this program as quickly as we can to bring this investigational combination to HCV specialists and their patients."

According to the FDA, the designation of an investigational drug as a Breakthrough Therapy 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.

Chronic hepatitis C is a priority focus of research and development at Merck. MK-5172 and MK-8742 are being investigated in a broad clinical program that includes studies in patients with multiple HCV genotypes who are treatment-naïve, treatment failures as well as other important HCV subpopulations such as patients with cirrhosis and those co-infected with HIV. For more information please see www.clinicaltrials.gov.