Anadys begins ANA598 Phase IIb study for hepatitis C

Anadys Pharmaceuticals, Inc. announced today that it has initiated the planned Phase IIb study of ANA598 in combination with pegylated interferon and ribavirin.  The protocol for the study has been cleared by the United States Food and Drug Administration (FDA) and Health Canada.  Patient screening has begun and patient dosing is expected to commence within the next several weeks.  In the study ANA598 will be tested in both treatment-naive patients and treatment-experienced patients who failed a prior course of therapy with interferon and ribavirin.  ANA598 is the Company's direct-acting antiviral, or DAA, being developed for the treatment of hepatitis C.

"We are excited to initiate this Phase IIb study of ANA598," said James L. Freddo, M.D., Anadys' Senior Vice President, Drug Development and Chief Medical Officer.  "By establishing safety and efficacy in a greater number of patients, including those who have failed prior HCV treatment, we hope to position ANA598 as a highly attractive HCV agent ready for Phase III development."

Phase IIb Protocol Design

In the study, approximately 200 chronically infected genotype 1 hepatitis C patients are expected to receive ANA598 200 mg twice a day (bid) in combination with Pegasys® (peginterferon alfa-2a) and Copegus® (ribavirin, USP) (a current standard of care, or SOC) with a loading dose of 800 mg bid on day 1, while approximately 66 patients are to receive placebo and SOC.  Enrollment is expected to include approximately equal numbers of treatment-naive patients and patients who have failed a prior course of SOC, including difficult to treat prior null-responders.   The primary endpoint of the study is Sustained Virological Response 24 weeks after patients conclude all treatment, known as SVR24.  Anadys is conducting the study at sites within and outside the United States.

Naive Arm

Approximately 100 treatment-naive HCV patients are expected to receive ANA598 in combination with SOC and 33 treatment-naive HCV patients are to receive placebo plus SOC.  Treatment duration for naive patients will be response-guided; patients who achieve undetectable levels of virus at Week 8 and maintain undetectable levels of virus will be scheduled to conclude all treatment at Week 28.  For naive patients with detectable virus at Week 8 dosing with ANA598, or placebo, and SOC is planned to continue through Week 48.  The Company expects to receive Week 8 antiviral response data by the end of the second quarter of 2011, Week 12 antiviral response data in the third quarter of 2011 and Week 24 antiviral response data in the fourth quarter of 2011.

Treatment-Experienced Arm, Including Prior Null Responders

Approximately 80 patients who were partial responders during, or relapsers after, a prior course of therapy with SOC alone are expected to receive ANA598 in combination with SOC, and 33 corresponding patients are to receive placebo plus SOC.  Additionally, approximately 28 prior null responder patients are to receive ANA598 in combination with SOC.  All treatment-experienced patients who receive ANA598 are scheduled to receive triple combination therapy for 48 weeks.  For the treatment-experienced patients, the Company expects to receive Week 12 antiviral response data in the third quarter of 2011 and Week 24 antiviral response data in the fourth quarter of 2011.