Mericitabine

**Semantic type:** Pharmacologic Substance

**Definition:** 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.

**Synonyms:** - 2' alpha-fluoro-2' beta-methyl-3',5'-diisobutyryldeoxycytidine - 2'-deoxy-2'-fluoro-2'-c-methylcytidine Diisobutyrate - 3',5'-diisobutyryl PSI 6130 - MERICITABINE - PSI 6130 Diisobutyrate - R7128 - RG 7128 - RO-5024048