mericitabine + telaprevir + peginterferon alfa-2a + ribavirin

This is a four-drug combination regimen consisting of **mericitabine**, **telaprevir**, **peginterferon alfa-2a**, and **ribavirin**. The regimen was investigated for the treatment of *chronic hepatitis C virus (HCV) infection*, particularly in patients with genotype 1. - **Mericitabine** is a nucleoside analog inhibitor of HCV RNA-dependent RNA polymerase (NS5B), interfering with viral RNA replication. - **Telaprevir** is an inhibitor of the HCV NS3/4A protease, blocking viral polyprotein processing and viral replication. - **Peginterferon alfa-2a** is a pegylated form of recombinant interferon alfa-2a that binds to cellular interferon receptors, stimulating innate antiviral activity and modulating the immune response against HCV. - **Ribavirin** is a guanosine analog with multiple proposed mechanisms, including direct antiviral activity, inhibition of inosine-monophosphate dehydrogenase, immunomodulatory effects, and induction of lethal mutagenesis in viral RNA[1][3][7]. This four-drug combination was considered as part of an approach to enhance cure rates, especially in difficult-to-treat populations or patients with prior treatment failure.