Idenix Pharmaceuticals Highlights Progress in Three HCV Programs

- Interim analysis of 50 mg cohort demonstrates potent HCV antiviral activity at 14 days for IDX184, a nucleotide polymerase inhibitor, in combination with PegIFN/Ribavirin - IDX375, a non-nucleoside polymerase inhibitor, exhibited favorable pharmacokinetic properties in a Phase I healthy volunteer study - Clinical Trial Application filed in December 2009 for IDX320, a next-generation protease inhibitor


CAMBRIDGE, Mass., Jan. 11  /PRNewswire-FirstCall/ -- Idenix Pharmaceuticals, Inc. (NASDAQ:IDIX), a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases, today announced significant progress in three HCV programs. Idenix will provide a business update on these three HCV development programs and on its partnered programs during a presentation by Jean-Pierre Sommadossi, Ph.D., chairman and chief executive officer, to financial analysts and investors at the 28th Annual J.P. Morgan Healthcare Conference in San Francisco on Thursday, January 14 at 8:00 a.m. PST.

IDX184: Nucleotide HCV Polymerase Inhibitor

The phase II clinical trial, initiated in the fourth quarter of 2009, is a randomized, double-blind, placebo-controlled, sequential dose-escalation study evaluating the safety, tolerability, pharmacokinetics and antiviral activity of IDX184 in combination with pegylated interferon and ribavirin in treatment-naive HCV genotype 1-infected patients. Patients will receive a daily dose of IDX184 or placebo plus pegylated interferon and ribavirin for 14 days and then continue on pegylated interferon and ribavirin for an additional 14 days. Antiviral activity will be assessed at the 14-day and 28-day timepoints. Four dosing regimens of IDX184 ranging from 50 to 200 mg per day will be evaluated. In the 100 mg and 200 mg cohorts, QD and BID regimens will be compared. Each cohort includes 20 patients randomized 4:1, IDX184:placebo. This study is being conducted at multiple centers in the United States and Argentina.

Interim analysis of the first 10 patients randomized into the first cohort (50 mg QD):

                                                 Patients with Undetectable
                     Median Change in HCV RNA       Viral Load at Day 14
         Cohort         (log10) at Day 14               (