ANA598 combo cuts down hepatitis C virus to undetectable levels: Anadys

ANA598, an investigational drug against hepatitis C, is found effective in clinical studies, according to Anadys Pharmaceuticals, Inc.

Anadys has been studying the efficacy of ANA598 in combination with pegylated interferon and ribavirin (SOC) in HCV patients in a phase II study.

An interim analysis of data at four weeks for the first dose cohort showed that 56% 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% of patients receiving placebo plus SOC.

ANA598 was well tolerated through four weeks, with no serious adverse events reported.

Anadys expects to initiate dosing in this cohort in January 2010.

“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,” stated Steve Worland, Ph.D., President and CEO.

With this additional data and results of subsequent trials, ANA598 has 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.

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.

44 patients in 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.

No patient experienced viral rebound through week 4.

Safety and tolerability from the interim analysis appeared similar between the active and placebo arms, with reported adverse events generally typical for interferon and ribavirin.

The ANA598 study is being managed by the Duke Clinical Research Institute (DCRI) under the leadership of John McHutchison, M.D. and is being conducted at a number of clinical sites in the United States. An independent DMC is responsible for reviewing the safety data in the trial and has endorsed escalating to the second dose level of 400 mg bid.

ANA598 is a non-nucleoside inhibitor of the HCV RNA polymerase.

Anadys has completed three Phase I clinical studies of ANA598 that have demonstrated potent antiviral activity and good tolerability.

Anadys has completed two long-term chronic toxicology studies of ANA598 (26 weeks duration in rats and 39 weeks duration in monkeys).

Anadys has presented in vitro data supporting the use of ANA598 in combination with interferon-alpha as well as with direct antivirals currently in development. In particular, data has shown that ANA598 is synergistic in vitro with interferon-alpha as well as representative HCV protease and polymerase inhibitors.

ANA598 retains full activity in vitro against mutations conferring resistance to protease inhibitors, nucleoside polymerase inhibitors and non-nucleoside polymerase inhibitors that act at binding sites distinct from that of ANA598, and protease and nucleoside polymerase inhibitors retain full activity in vitro against mutations conferring resistance to ANA598.

ANA598 has received Fast Track Status from the FDA for the treatment of chronic hepatitis C.