sofosbuvir + velpatasvir + voxilaprevir + ribavirin

A four-drug combination regimen consisting of **sofosbuvir**, **velpatasvir**, **voxilaprevir**, and **ribavirin**, developed together for the treatment of chronic hepatitis C virus (HCV) infection, especially in patients who have previously failed direct-acting antiviral therapies. - Sofosbuvir is a nucleotide analog HCV NS5B polymerase inhibitor, blocking viral RNA synthesis. - Velpatasvir inhibits HCV NS5A, a viral protein that impacts RNA replication and assembly. - Voxilaprevir is an HCV NS3/4A protease inhibitor, preventing viral polyprotein processing. - Ribavirin is a nucleoside analog with broad-spectrum antiviral activity; its precise mechanism in HCV is not fully defined but is thought to involve inhibition of viral RNA synthesis and immune modulation. This combination has been studied for salvage therapy in patients with chronic HCV infection, including those with and without cirrhosis[3].