ledipasvir + sofosbuvir + vedroprevir + ribavirin

A combination therapy consisting of four direct-acting antiviral agents: **ledipasvir** (an HCV NS5A inhibitor), **sofosbuvir** (a nucleotide analog HCV NS5B RNA polymerase inhibitor), **vedroprevir** (also known as GS-9451, an HCV NS3 protease inhibitor), and **ribavirin** (a guanosine analog antiviral). This combination is investigated for the treatment of **chronic hepatitis C virus (HCV) infection**, especially genotype 1. Mechanistically, they target multiple sites of viral replication and assembly: - Ledipasvir inhibits the NS5A protein, critical for viral RNA replication and assembly. - Sofosbuvir acts as a chain terminator during HCV RNA synthesis by the viral RNA-dependent RNA polymerase (NS5B). - Vedroprevir targets and inhibits the NS3/4A protease, essential for HCV polyprotein processing and viral replication. - Ribavirin is a broad-spectrum antiviral, thought to interfere with viral replication via multiple mechanisms, including lethal mutagenesis and immune modulation. The combination's multi-targeted approach aims for potent suppression of HCV replication and improved rates of sustained virologic response (SVR). Clinical studies have evaluated various combinations of these agents—with and without ribavirin or peginterferon—in both treatment-naive and experienced patients, including those with cirrhosis.