Voxilaprevir (GS-9857) is a noncovalent, reversible inhibitor of HCV NS3/4A protease inhibitor (PI) with pangenotypic antiviral activity. Voxilaprevir inhibits genotype 1b and 3a wild-type NS3 proteases with Ki values of 0.038 nM and 0.066 nM, respectively. Voxilaprevir is an orally active direct-acting antiviral agent (DAA) and can be used for HCV infection research[2].IC50 & Target: Hepatitis C virus (HCV) nonstructural protein (NS) 3/4A proteaseIn Vitro: NS3/4A protease is essential for proteolytic cleavage of the HCV encoded polyprotein (intomature forms of NS3, NS4A, NS4B, NS5A and NS5B proteins) and hence for viral replication.In enzymatic assays using recombinant NS3 protease domains and isogenic NS4A peptide cofactors provided in trans. Voxilaprevir is against HCV genotype 1b and 3a NS3 proteases with Ki values of 0.038 nM and 0.066 nM, respectively.In stable cell lines (Huh-7-Lunet or Huh7-1C cells) expressing renilla luciferase-encoding HCV replicons. Voxilaprevir exhibits potent pangenotypic antiviral activity with EC50 ranging from 0.33 to 6.6 nM across genotypes 1 to 6. Voxilaprevir is against HCV replicon strain DQ314805, H77, Con1, JFH-1, J6,J8 (full length) and HM568433, SA13 (NS3 Chimera) with IC50 values of 0.33 nM, 3.9 nM, 3.3 nM, 3.7 nM, 4.5 nM, 1.8 nM, and 6.6 nM, 1.9 nM, respectively.