Elbasvir (MK-8742) is an inhibitor of nonstructural protein 5A (NS5A) of hepatitis C virus (HCV) being developed as a component of treatment regimens for chronic HCV infection.

NS5A:2.2 pM (EC50)

Elbasvir potently inhibits hepatitis C virus (HCV) non-structural protein 5A (NS5A) with an EC50 value of 2.2 pM in Huh7 human liver cancer cells expressing pH77S.3/GLuc2A, a cell-culture adapted HCV16 genotype 1a derivative and luciferase reporter, following a 48-hour exposure in vitro [1,2]. NS5A is essential for HCV RNA synthesis and viral assembly, and elbasvir inhibits the assembly of new viral replicase complexes when used at a concentration of 50 pM [2]. It exhibits potent inhibitory activity against a broad range of HCV genotypes with EC50 values of 0.0002-34 nM in Huh7 cells expressing replicons of HCV genotype 4 NS5A and EC50 values of less than 0.2 nM for replicons from all other tested genotypes except 2b [1,3,4]. Formulations containing elbasvir have been used alone and in combination with NS3/4A protease inhibitors in the treatment of HCV.