Anadys Pharmaceuticals, Inc announced preliminary results from a planned interim analysis of data at four weeks for the first dose cohort, 200 mg bid, in an ongoing phase-II study of ANA598 in combination with pegylated interferon and ribavirin (SOC) in HCV patients. In all 56 per cent of patients receiving ANA598 plus SOC achieved undetectable levels of virus (<15 IU/ml) at week 4, known as Rapid Virological Response or RVR, compared to 20 per cent of patients receiving placebo plus SOC.

ANA598 was well tolerated through four weeks, with no serious adverse events reported. An independent Data Monitoring Committee (DMC) has endorsed escalating to the second dose level, 400 mg bid, and this cohort is now open for enrolment. Anadys expects to initiate dosing in this cohort in January 2010.

“We are very pleased with the 4-week antiviral response and safety for this first dose cohort,” said Steve Worland, president and CEO. “We look forward to the upcoming 12-week data, including antiviral response known as cEVR, for the 200 mg bid cohort in the first quarter of 2010 as well as RVR and cEVR data for the 400 mg bid cohort in the second quarter of 2010. With this additional data and results of subsequent trials, we hope to see ANA598 established as the leading non-nucleoside in HCV, suitable for combination with current standard of care as well as with other direct antivirals currently in development.”

“This first phase-II data clearly demonstrates the ability of ANA598 to improve antiviral response at week 4 above what is seen with current standard of care alone,” said James L Freddo, senior vice president, Drug Development and chief medical officer. “The RVR rate combined with a good safety and tolerability profile to date is encouraging for the prospects of ANA598 contributing to improved long-term treatment outcomes as measured by SVR.”

In the ongoing phase-II study, patients are to receive ANA598 or placebo, added to SOC, for 12 weeks, after which they are to continue receiving SOC alone for 12 or 36 additional weeks. The results announced today are from a scheduled interim analysis following four weeks of dosing in the first of two planned dose cohorts. Total 44 patients in two the first cohort (34 genotype 1a and 10 genotype 1b) received at least one dose of study medications, 29 receiving ANA598 and 15 receiving placebo. Two patients who withdrew consent during the first week of dosing for reasons unrelated to ANA598 are excluded from the analysis of antiviral response but included in the safety database.

Reported antiviral response data is as of week four. Reported safety data is as of an interim analysis date which was reached shortly after the last enrolled patient completed four weeks of dosing, and includes information through week four for all patients plus information subsequent to week four for those patients who had earlier enrolment dates.

No patient experienced viral rebound (defined as >1 log10 increase from a prior measurement) through week four. In accordance with the study protocol, four patients (three genotype 1a patients receiving placebo plus SOC and one genotype 1b patient receiving ANA598 plus SOC) discontinued either ANA598 or placebo at week four due to failing to reach at least one log10 viral load decline.

ANA598 is a non-nucleoside inhibitor of the HCV RNA polymerase and is wholly-owned by Anadys. Anadys has completed three phase-I clinical studies of ANA598 that have demonstrated potent antiviral activity and good tolerability.