mericitabine + boceprevir + peginterferon alfa-2a + ribavirin

**Mericitabine + boceprevir + peginterferon alfa-2a + ribavirin** is a four-drug antiviral therapy regimen used experimentally in the treatment of chronic hepatitis C virus (HCV) infection, especially genotype 1. Each component acts at different steps of the HCV replication cycle: - **Mericitabine** is a nucleoside analog inhibitor of HCV RNA polymerase, targeting the viral NS5B polymerase to inhibit viral RNA synthesis. - **Boceprevir** is a small molecule inhibitor of the HCV NS3/4A protease, blocking viral polyprotein processing and replication. - **Peginterferon alfa-2a** is a pegylated interferon biologic that induces an antiviral state in host cells and modulates immune response to enhance clearance of infected hepatocytes. - **Ribavirin** is a nucleoside analog with multiple proposed antiviral mechanisms, including inhibition of viral RNA-dependent RNA polymerase and immunomodulation. This combination is considered in patients with HCV to improve sustained virologic response (SVR) rates, especially in cases where other regimens have limited efficacy or resistance arises. All drugs have synergistic antiviral effects when used in combination, especially in genotype 1 HCV infections.