Pharmasset selects new development candidate for hepatitis C

PSI-7851 is a proprietary nucleotide analogue polymerase inhibitor of hepatitis C virus (HCV) that is being advanced into good laboratory practice animal toxicity studies required for submission of an investigational new drug application with the FDA or an equivalent foreign regulatory filing.

PSI-7851 has demonstrated in vitro anti-HCV activity with EC90 values of 0.31 +/- 0.12 uM, which is approximately 15- to 20-fold more potent than the active metabolite of R7128, PSI-6130. In vitro studies of PSI-7851 have not shown evidence of any mitochondrial or other cellular toxicities that may be associated with some nucleoside analogs.

Michael Otto, Pharmasset’s chief scientific officer, said: “We anticipate completing the required animal toxicity studies and filing an IND in the first quarter of 2009.”