Setrobuvir (ANA-598) is an investigational antiviral compound developed for the treatment of hepatitis C virus (HCV) infection. It functions as a non-nucleoside inhibitor of the HCV NS5B RNA-dependent RNA polymerase, an enzyme critical for viral replication. By binding to an allosteric site on the polymerase, Setrobuvir disrupts the enzyme's activity, thereby suppressing viral replication in infected individuals.

The compound was studied in early-phase clinical trials as part of combination antiviral regimens, particularly with other direct-acting antivirals such as protease inhibitors or nucleoside analogs. Its development aimed to improve sustained virologic response rates, especially in patients with genotype 1 HCV, which is historically more difficult to treat.

Although Setrobuvir showed promising antiviral activity in initial studies, its development was discontinued due to challenges related to drug-drug interactions, variable pharmacokinetics, and the emergence of more potent and safer HCV therapies. Nonetheless, it contributed to the understanding of non-nucleoside polymerase inhibitors and helped shape the design of subsequent antiviral agents in the fight against hepatitis C.