ACH-3422

ACH-3422 is an investigational oral small-molecule uridine-analog nucleotide prodrug that inhibits the hepatitis C virus (HCV) NS5B RNA-dependent RNA polymerase, thereby blocking viral RNA replication. It was developed by Achillion Pharmaceuticals (later acquired by Alexion Pharmaceuticals and subsequently part of AstraZeneca) as a core component of all-oral direct-acting antiviral regimens, including combinations with the NS5A inhibitor ACH-3102 and potentially an NS3/4A protease inhibitor, for the treatment of chronic genotype 1 and other genotypes of HCV infection.[1][3][4][5][9][13] In Phase 1 studies, ACH-3422 demonstrated dose-related antiviral activity in HCV-infected patients, with multi-log10 reductions in viral load and a safety profile supportive of further development, but the program was ultimately suspended at an early clinical stage.[4][5][6][9][11][13]