Effect of oral administration of emtricitabine on woodchuck hepatitis virus replication in chronically infected woodchucks

Emtricitabine [(-)FTC] [(-)-beta-2',3'-dideoxy-5-fluoro-3'-thiacytidine] ha s been shown to be an effective inhibitor of hepatitis B virus (HBV) in cel l culture, with a potency and selectivity that are essentially identical to those of lamivudine. The antiviral activity of oral administration of (-)F TC against WHV replication in chronically infected woodchucks, an establish ed and predictive model for antiviral therapy against HBV, was examined in a placebo-controlled study. (-)FTC significantly reduced viremia and intrah epatic WHV replication in a dose-dependent manner that was comparable to th e antiviral activity of lamivudine observed in previous studies conducted b y our laboratories. No effect on the levels of hepatic WHV RNA or the level s of woodchuck hepatitis surface antigen or anti-woodchuck hepatitis surfac e and core antibodies in the serum of the treated animals was observed. No evidence of drug-related toxicity was observed in any of the animals treate d.