Positive data from Anadys' setrobuvir Phase IIb combination study on genotype 1 HCV

Anadys Pharmaceuticals, Inc. (Nasdaq: ANDS) today released interim antiviral response and safety data from an ongoing Phase IIb study of setrobuvir in combination with pegylated interferon and ribavirin (P/R) in genotype 1 hepatitis C patients.  Setrobuvir is the Company's direct-acting antiviral being developed for the treatment of chronic hepatitis C, or HCV.

"We are pleased with today's data, which we believe demonstrate a compelling profile for setrobuvir in significantly more patients," said Steve Worland, Ph.D., President and CEO of Anadys.  "The antiviral response in patients who had failed prior treatment is a particularly encouraging benchmark of setrobuvir's potency and high barrier to resistance.  Coupled with a favorable safety profile to date, we believe today's data position setrobuvir as a very attractive agent to be included in future DAA combination regimens."

78% of treatment-naive patients and 76% of patients who had responded inadequately to, or relapsed after, prior treatment with P/R had undetectable virus at week 12 (cEVR) while receiving setrobuvir plus P/R, compared to 56% and 44%, respectively, for patients who received placebo plus P/R.  71% of treatment-naive patients who received setrobuvir plus P/R had undetectable virus at week 8 and met the initial response-guided criteria for shortening treatment in this study to 28 weeks from the traditional 48 weeks for treatment with P/R alone.  

29% of patients who had no appreciable response to prior treatment with P/R (null responders) achieved cEVR with setrobuvir plus P/R, and the percentage of patients with undetectable virus continued to climb in this hard-to-treat population to 36% at week 18.  No prior null responders received placebo plus P/R in this trial.

The viral breakthrough rate through 12 weeks on setrobuvir plus P/R was low in both treatment-naïve patients (2.9%) and patients who had responded inadequately to, or relapsed after, prior treatment with P/R (3.6%).  The Company believes this low incidence of viral breakthrough exhibited to date in a larger patient population further characterizes setrobuvir's high barrier to resistance.

Setrobuvir has been generally well-tolerated in the study.  Safety data for patients receiving setrobuvir plus P/R, and comparison to the control group that received placebo plus P/R, are being reported through a time period that reflects a median dosing duration of 19 weeks.  The rate of discontinuing treatment in the study due to adverse events has been similar in patients receiving setrobuvir plus P/R (5.6%) or P/R alone (5.9%).  The profile of adverse events has been similar between the setrobuvir and control groups, with reported adverse events being typical for patients treated with interferon and ribavirin.  In the setrobuvir group, 39% of patients (84/215) developed a rash while 22% (15/68) of patients in the control group developed a rash.  98% of the rashes in the setrobuvir group were mild or moderate (grade 1 or grade 2), compared to 93% in the control group.  There were no Grade 4 rashes in either group.  The incidence of rash in the setrobuvir group is consistent with prior reports of rash due to interferon and ribavirin through 19 weeks of treatment.