Elbasvir (MK-8742) is a hepatitis C virus nonstructural protein 5A (HCV NS5A) inhibitor with EC50s of 4, 3 and 3 nM against genotype 1a, 1b, and 2a, respectively.
Elbasvir shows potent activity against genotype 1a and 1b replicons, with EC90 of 0.006 nM for both the wild-type 1a_H77 and 1b_con1 replicons. Elbasvir inhibits genotype 3 replicons with EC90 of 0.12 nM. Elbasvir (0.06 nM, 0.6 nM, and 6 nM) demonstrates dose-dependent suppression of resistant genotype 1a replicons, illustrated by the reductions in colony counts at higher doses[1]. Elbasvir is highly potent against HCV replicons bearing NS5A sequences from GT1a, -1b, -2a(31L), -3a, -4a, -5a, and -6, with EC50s in the low-picomolar range[2].
[1]. Liu R, et al. Susceptibilities of genotype 1a, 1b, and 3 hepatitis C virus variants to the NS5A inhibitor Elbasvir. Antimicrob Agents Chemother. 2015 Nov;59(11):6922-6929. [2]. Lahser FC, et al. The Combination of Grazoprevir, a Hepatitis C Virus (HCV) NS3/4A Protease Inhibitor, and Elbasvir, an HCV NS5A Inhibitor, Demonstrates a High Genetic Barrier to Resistance in HCV Genotype 1a Replicons. Antimicrob Agents Chemother. 2016 A