Positive Two-Year Data for Telbivudine for the Treatment of Chronic Hepatitis B Presented at 2005 Digestive Disease Week (DDW) M

Positive Two-Year Data for Telbivudine for the Treatment of
Chronic Hepatitis B Presented at 2005 Digestive Disease Week (DDW) Meeting
Telbivudine treatment nearly doubles proportion of patients achieving clinical
efficacy measures compared to lamivudine



CHICAGO, May 16  /PRNewswire-FirstCall/ -- Idenix Pharmaceuticals, Inc.
(NASDAQ:IDIX) today announced the presentation of interim two-year results from
an extended-treatment phase IIb clinical trial for telbivudine demonstrating
continuing advantages compared to lamivudine across key efficacy endpoints
through two years of treatment in HBeAg-positive chronic hepatitis B patients.
Further analyses of the two-year data indicate that the link between early and
profound viral suppression and markers of improved clinical outcomes that were
demonstrated at one year extends through two years of treatment. These data
were presented today at the 2005 Digestive Disease Week meeting in Chicago,
Illinois by Ching-Lung Lai, M.D., lead investigator and Professor of Medicine
and Hepatology, Department of Medicine, University of Hong Kong.

The ongoing phase IIb clinical trial compares telbivudine monotherapy and a
combination of telbivudine and lamivudine, with lamivudine monotherapy in 104
treatment-naive patients with HBeAg-positive chronic hepatitis B. Patients
receiving telbivudine monotherapy achieved a 1.5 log10, or 30-fold, greater
mean viral load reduction compared to patients receiving lamivudine monotherapy
at two years.  At two years, the percent of patients receiving telbivudine
monotherapy in whom levels of serum HBV DNA became undetectable by a sensitive
PCR-based assay was 71 percent, more than double that of the 32 percent of
patients receiving lamivudine monotherapy (p