TELBIVUDINE

地天泰

IDENIX PHARMACEUTICALS, INC. PRESENTS FINAL 1 YEAR RESULTS FOR LEAD HEPATITIS B TREATMENT CANDIDATE, TELBIVUDINE

Rapid and marked suppression of hepatitis B virus may improve clinical outcome

Berlin, 16 April 2004 - Idenix Pharmaceuticals, Inc. today presented one year data from a randomized, double-blind multinational phase IIb clinical trial comparing treatment with telbivudine alone or treatment with a combination of telbivudine plus lamivudine, with lamivudine monotherapy in patients with chronic hepatitis B. The study results indicate that patients treated with telbivudine achieved significantly greater reduction of hepatitis B virus (HBV) replication and higher rates of normalization of ALT (a measure of liver disease) compared with lamivudine monotherapy. These data were presented by Steven Han, M.D., Professor at the UCLA School of Medicine's Division of Digestive Diseases, and one of the lead U.S. investigators in the phase IIb clinical trial, at the 39th meeting of the European Association for the Study of the Liver (EASL). Further analyses of the study data indicate a correlation between the rapid and significant antiviral activity seen in telbivudine-treated patients and markers of improved clinical benefit at one year. Additional details regarding these analyses are being presented at the EASL conference in a separate session by Dr. Thierry Poynard, Professor of Medicine at the Hôpital La Pitié Salpêtrière, Paris, France.

After one year of treatment, patients receiving telbivudine experienced marked suppression of HBV replication, with a mean reduction in viral load of >6 log10 (1 million-fold). This was a significantly greater antiviral response compared with patients receiving lamivudine alone (4.57 log10 reduction, or 50,000-fold). Additionally, nearly twice the percentage of patients treated with telbivudine monotherapy experienced reductions in levels of serum HBV below the detection limit of a highly sensitive assay compared with those patients receiving lamivudine monotherapy, 61 percent and 32 percent respectively. The level of serum ALT became normal in significantly more patients in the telbivudine monotherapy groups than patients in the lamivudine monotherapy group, 86 percent and 63 percent respectively.

Data from the telbivudine/lamivudine combination treatment arms demonstrated an increase in antiviral efficacy when compared to lamivudine monotherapy but there was no advantage of the telbivudine/lamivudine combination treatment over telbivudine alone, with regard to antiviral or clinical effects.

All five treatment regimens were well-tolerated with no safety issues identified for the duration of the one-year treatment period. There were no drug-attributed serious adverse events, and no pattern of dose-related or treatment-related clinical side effects or laboratory abnormalities.

About Telbivudine
Telbivudine is a specific and selective, oral, once-daily nucleoside being developed for the treatment of chronic hepatitis B. To date, preclinical and clinical data demonstrate a favorable safety profile and marked antiviral activity against HBV. This drug candidate is being developed by Idenix in collaboration with Novartis Pharma AG under a development and commercialization agreement established in May 2003.

Telbivudine is currently being evaluated in a two-year international phase III clinical trial comparing telbivudine to lamivudine. The trial includes more than 1,200 patients, both HBeAg+ and HBeAg-, with compensated liver disease. This trial is being conducted at approximately 135 clinical sites located in 20 countries in Europe, North America and Asia. If the phase III clinical trial data are positive, Idenix, working jointly with Novartis, currently expects to commence the submission of worldwide marketing applications, beginning with a U.S. New Drug Application filing in late 2005.