Merck discontinues HCV candidates

Merck & Co. Inc. (NYSE:MRK) discontinued development of MK-3682B (grazoprevir/ruzasvir/uprifosbuvir) and MK-3682C (ruzasvir/uprifosbuvir), emptying its pipeline of candidates to treat HCV infection. The pharma based its decision on a review of Phase II efficacy data for the combination products, and in consideration of the “evolving marketplace” with an expanding number of treatment options for chronic HCV infection, including its own marketed drug Zepatier elbasvir/grazoprevir.

Merck gained uprifosbuvir (MK-3682), a component of MK-3682B and MK-3682C, through its $3.9 billion acquisition of Idenix Pharmaceuticals Inc. in 2014. The compound is a uridine nucleotide analog HCV NS5B polymerase inhibitor. MK-3682B combines grazoprevir (MK-5172), an HCV NS3/4A protease inhibitor; ruzasvir (MK-8408), an HCV NS5A protein inhibitor; and uprifosbuvir. MK-3682C comprises ruzasvir and uprifosbuvir (see BioCentury, Jun 16, 2014)...