Dasabuvir is a non-nucleoside inhibitor of the hepatitis C virus (HCV) non-structural protein 5B (NS5B), an RNA-dependent RNA polymerase, with potential activity against HCV. Upon administration and after intracellular uptake, dasabuvir binds HCV NS5B polymerase and blocks viral RNA synthesis and replication. The HCV NS5B protein is essential for the replication of the HCV RNA genome.