Merck HCV combo regains breakthrough in smaller population

Merck & Co. Inc. (NYSE:MRK) said FDA granted grazoprevir/elbasvir ( MK-5172/ MK-8742) breakthrough therapy designations to treat HCV genotype 4 infection and HCV genotype 1 infection in patients with end stage renal disease on hemodialysis.

In January, FDA said it would rescind breakthrough designation for the combo to treat a broader indication, chronic HCV infection, due to the availability of other HCV drugs. FDA had granted that designation in 2013. ...