Velpanat 400 mg/100 mg is a brand-name medication used to treat chronic Hepatitis C virus (HCV) infection. It contains two active ingredients: Sofosbuvir (400 mg) Velpatasvir (100 mg) Together, these two drugs are classified as direct-acting antivirals (DAAs). They work by stopping the virus from multiplying in your body. It is effective against all six major genotypes (1 to 6) of HCV.Over 95% sustained virologic response (SVR) – meaning the virus becomes undetectable in the blood 12 weeks after treatment ends (considered a "functional cure").