ledipasvir + GS-9451 + tegobuvir + ribavirin

This is a **four-drug combination regimen** being investigated for the treatment of **chronic hepatitis C virus infection (HCV), particularly genotype 1**. - **Ledipasvir** is an HCV NS5A inhibitor that blocks viral replication. - **GS-9451** is a nonstructural protein NS3 protease inhibitor, targeting a key element in HCV’s replication cycle. - **Tegobuvir (GS-9190)** is an imidazopyridine inhibitor, acting on the HCV NS5B polymerase at an allosteric site. - **Ribavirin** is a nucleoside analogue antiviral, incorporated to boost efficacy, especially in difficult-to-treat populations. This regimen represents an oral, all-direct-acting antiviral approach (without interferon), targeting multiple essential steps in the HCV lifecycle. It has been studied in phase 2 clinical trials for safety and efficacy in HCV genotype 1-infected adults[3][5].