Valeant Pharmaceuticals reports promising 24-week interim data from a Phase 2 study of its oral antiviral compound pradefovir. The company is evaluating the safety and efficacy of pradefovir for the treatment of compensated chronic hepatitis B. Following is an edited version of the Valeant announcement:

Pradefovir is a prodrug of adefovir dipivoxil (Hepsera) that was licensed from Metabasis Therapeutics. Pradefovir uses Metabasis’ HepDirect™ technology which enables higher concentrations of the drug in the liver, the primary site of hepatitis B viral (HBV) replication.

The Phase 2 study is an open-label, randomized, multiple dose study with 242 patients enrolled at 21 sites in the United States, Taiwan, Singapore and Korea. Approximately half of the patients had been previously treated unsuccessfully with other drugs and 70 percent of the patients were HBeAg positive. Patients that have been previously treated ineffectively are considered to be more difficult to treat.

The Phase 2 study consists of five treatment groups: pradefovir – 5, 10, 20 and 30 mg/day (QD), and Hepsera – 10 mg/day (QD), with an overall treatment duration of 48 weeks. The interim 24-week data indicate that pradefovir demonstrated a significant decline in HBV DNA summarized as follows:

Pradefovir Phase 2 Study: 24-week Interim Results

The interim results have shown no evidence of nephrotoxicity. There were no serious adverse events related to treatment. The most frequently reported adverse events were similar across all treatment groups, including Hepsera. No dose-related trends regarding safety were identified and no events resulted in a patient being withdrawn prematurely from treatment. Kim D. Lamon, M.D., Ph.D., president, research and development and chief scientific officer, said, “The pradefovir interim results are very promising and better than expected, particularly in a study where approximately half of the patients previously received therapy that was ineffective. Current treatment medicines have encountered resistance after prolonged use and some have dose-limiting adverse events. If the clinical results continue to be successful, pradefovir could provide physicians with a new treatment alternative that will significantly improve patient outcomes.”

The detailed Phase 2 interim results are expected to be submitted for presentation at the 56th Annual Meeting of the American Association for the Study of Liver Diseases  (56^th AASLD) to be held in November 2005. Patient participation in the Phase 2 trial is expected to be completed early in 2006. Valeant plans to review the interim results with the Food and Drug Administration (FDA).

About Valeant

Valeant Pharmaceuticals International is a global, publicly traded, research-based specialty pharmaceutical company that discovers, develops, manufactures and markets pharmaceutical products primarily in the areas of neurology, infectious disease and dermatology. More information about Valeant can be found at www.valeant.com

07/22/05

Source
Valeant Pharmaceuticals. Valeant Pharmaceuticals Reports Promising Data from Pradefovir Mesylate Phase 2 Study. Press Release. July 19, 2005.