idx320 + idx184

IDX320 + IDX184 is an **investigational oral combination therapy** for the treatment of chronic hepatitis C virus (HCV) infection, consisting of two direct-acting antiviral agents: IDX320, a macrocyclic NS3/4A protease inhibitor, and IDX184, a liver-targeted nucleotide prodrug of 2'-methylguanosine monophosphate acting as a polymerase inhibitor. IDX320 is designed to block HCV replication by inhibiting the viral protease, while IDX184 inhibits the HCV NS5B RNA-dependent RNA polymerase. Both drugs were developed by Idenix Pharmaceuticals, aiming for synergistic effects in HCV viral load reduction. The combination showed potent antiviral activity in preclinical and early clinical studies targeting multiple HCV genotypes, with additive or mildly synergistic effects. However, a clinical hold was placed in 2010 due to liver safety concerns in a drug-drug interaction study, and development was not resumed after this event.