( re permitted to roll over topegylated ...)Valopicitabine Combined with Standard of Care Cleared Hepatitis C,Virus in 72% of Patients Who Completed 12 Weeks of Treatment in a,Phase II Trial,Health

"These results support our hypothesis that valopicitabine can be administered in combination with pegylated interferon and ribavirin," said Douglas Mayers, M.D., executive vice president and chief medical officer of Idenix Pharmaceuticals. "We are very pleased with the viral kinetics and HCV RNA clearance rates observed in patients treated with triple combination therapy in this study and look forward to further development of this combination."

About Valopicitabine

Valopicitabine is an investigational nucleoside polymerase inhibitor being evaluated in ongoing clinical trials for the treatment of hepatitis C. The most common adverse events reported in valopicitabine clinical trials to date include nausea, vomiting, fatigue, diarrhea, headache, flu-like symptoms and depression. Idenix is developing valopicitabine in collaboration with Novartis Pharma AG.

About Hepatitis C

HCV infection is the most common chronic blood-borne infection in the United States.(1) The Centers for Disease Control and Prevention estimates that 4 million Americans have been infected with HCV, and 2.7 million of these carry chronic HCV infections.(2) Hepatitis C-related liver failure is the most common indication for liver transplantation in the United States.(2) As the prevalence of severe liver disease attributable to hepatitis C rises, deaths due to complications from hepatitis C infection, currently 8,000 to 10,000 per year in the United States, are increasing and are expected to triple by 2010.(3)

Conference Call Information

Idenix will hold a conference call today at 8:30 a.m. EDT. To access the call please dial (800) 774-5358 U.S./Canada or (706) 758-9475 International and enter passcode 3143678 or to listen to a live webcast of the call, go to "Calendar of Events" in the Idenix Investor Center at
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