(2'R)- 2'-Deoxy-2'-fluoro-2'-methylcytidine 3',5'-bis(2-methylpropanoate)

Mericitabine has been investigated for the treatment of Hepatitis C, Chronic. Mericitabine is a polymerase inhibitor being developed for the treatment of chronic hepatitis C. Mericitabine is a prodrug of PSI-6130, which demonstrated excellent potency in preclinical studies. PSI-6130 is a pyrimidine nucleoside analog inhibitor of HCV RNA polymerase, an enzyme that is necessary for hepatitis C viral replication.|Mericitabine is an orally available prodrug of PSI-6130 which is a selective cytidine nucleoside analogue and non-cytotoxic hepatitis C virus (HCV) polymerase inhibitor. After intracellular uptake, mericitabine is phosphorylated into two active triphosphate metabolites, which disable HCV RNA-dependent RNA polymerase (non-structural protein 5B; NS5B) upon binding. This results in the blockage of viral HCV RNA production and thus viral replication. This agent has a high barrier to resistance, however, a substitution mutation (S282T) on HCV NS5B impairs mericitabine's activity significantly.

Mericitabine (RG 7128; R-7128) is a nucleoside inhibitor of the HCV NS5B polymerase that acts as an RNA chain terminator and prevents elongation of RNA transcripts during replication.