Anadys Pharmaceuticals, Inc., a biopharmaceutical company committed to the discovery, development and commercialization of novel anti-infective medicines, has initiated a Phase I clinical trial of ANA975 in healthy volunteers.

ANA975 is an oral prodrug of Anadys' proprietary small molecule compound isatoribine, an agonist of Toll-Like Receptor 7 (TLR7). Results from clinical trials of isatoribine have demonstrated a statistically significant viral load reduction in hepatitis C patients by activating innate immunity.

"We expect that ANA975 will provide the same combination of anti-viral effect and tolerability as observed with isatoribine, but with the added advantage of oral administration," Steve Worland, Anadys' executive vice president, Research and Development said adding, "The pharmaceutical properties of ANA975 along with the preclinical data further support our belief that ANA975 provides the potential to become an orally administered frontline treatment for chronic hepatitis C virus (HCV) infection."

The Phase I clinical trial is designed to evaluate the safety, tolerability and pharmacokinetics of ANA975 in healthy volunteers. The study is an open-label, ascending single-dose evaluation of ANA975 to be administered orally to a total of 18 subjects in three cohorts at 400 mg, 800 mg and 1200 mg doses. The trial is being conducted in the UK.

ANA975 is an oral prodrug of Anadys' proprietary compound isatoribine. To date, isatoribine has been administered to 64 subjects, including 44 patients chronically infected with hepatitis C. Data from the Phase IB clinical trial of isatoribine, presented at the American Association for the Study of Liver Diseases (AASLD) 2004 Annual Meeting in Boston, provided the first reported evidence that a selective agonist of TLR7 can reduce circulating levels of HCV by activating innate immunity.