Voxilaprevir is a Direct-Acting Antiviral (DAA) medication used as part of combination therapy to treat chronic Hepatitis C, an infectious liver disease caused by infection with Hepatitis C Virus (HCV). Sofosbuvir/velpatasvir/voxilaprevir (Vosevi) is indicated for adult patients with chronic HCV without cirrhosis or with compensated cirrhosis who have (1) genotype 1 through 6 and have previously been treated with an NS5A inhibitor or (2) genotype 1a or 3 and have previously been treated with sofosbuvir without an NS5A inhibitor. Voxilaprevir exerts its antiviral action by reversibley binding and inhibiting the NS3/4A serine protease of Hepatitis C Virus (HCV). Following viral replication of HCV genetic material and translation into a single polypeptide, Nonstructural Protein 3 (NS3) and its activating cofactor Nonstructural Protein 4A (NS4A) are responsible for cleaving genetic material into the following structural and nonstructural proteins required for assembly into mature virus: NS3, NS4A, NS4B, NS5A, and NS5B. By inhibiting viral protease NS3/4A, voxilaprevir therefore prevents viral replication and function.