Anadys Pharmaceuticals has initiated dosing in its Phase IIb study of ANA598, which is being tested in combination with pegylated interferon and ribavirin in hepatitis C patients.

The study will evaluate ANA598, the company’s direct-acting antiviral, in both treatment-naive patients and patients who have failed a prior course of hepatitis C therapy with interferon and ribavirin.

The study will enrol approximately 275 patients.

The primary endpoint of the study will be sustained virological response 24 weeks after patients complete treatment.

The company expects to receive week-24 antiviral response results for both the treatment groups in the fourth quarter of 2011.