icon-folder.gif   Conference Reports for NATAP  
  57th Annual Meeting of the American Association
for the Study of Liver Diseases
October 27-31, 2006
Boston, MA
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Update on NM283, HCV Polymerase Inhibitor, at New 200 mg Dose
The study results will be reported at AASLD Monday morning in the oral session. Reported by Idenix.
Boston, October 27, 2006 - Idenix Pharmaceuticals, Inc. (NASDAQ: IDIX) today announced interim results of the phase IIb clinical trial of its hepatitis C investigational therapy, valopicitabine, dosed in combination with pegylated interferon. In this study, 200 mg/day of valopicitabine, combined with pegylated interferon, resulted in favorable viral suppression with a low rate of side effects in treatment naive patients with genotype-1 HCV infection after 24 weeks of treatment. The results will be presented at the 57th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) in Boston, Massachusetts.
"We are very excited about these preliminary results at Idenix because they further validate our valopicitabine development program in treatment naive patients," said Jean-Pierre Sommadossi, Ph.D., chairman and chief executive officer of Idenix Pharmaceuticals. "The observed synergistic activity demonstrated in this trial between valopicitabine and pegylated interferon has reinforced our belief that valopicitabine has potential to be a part of HCV combination treatments. We have initiated a drug-drug interaction study with ribavirin and, if successful, will possibly evaluate double and triple combination regimens in phase III trials."
At 24 weeks, the 200 mg/day dose of valopicitabine in combination with pegylated interferon achieved marked HCV RNA reductions in treatment naive patients with genotype-1 infection. A mean 4.24 log10 reduction in viral load was achieved among patients being treated with 200 mg/day of valopicitabine, in combination with pegylated interferon. Approximately 68 percent (23/34) of patients receiving this combination regimen achieved viral clearance at week 24, utilizing the Taqman assay's lower limit of quantification of 20 IU/mL.
"These data are very encouraging because they demonstrated that the combination of valopicitabine and pegylated interferon cleared viral load in many patients at six months," said Douglas Dieterich, M.D., Professor of Medicine at the Mt. Sinai School of Medicine, New York and an investigator in the study. "Direct-acting antivirals are likely to be the key components of HCV combination treatments in the future. As the most advanced polymerase inhibitor in clinical development, valopicitabine could have a potential role in these future combination therapies."
About the Phase IIb Study Design
The 24-week analysis from this ongoing 48-week phase IIb clinical trial in treatment-naive HCV patients included data from the following five randomized treatment arms, all involving dosing regimens of valopicitabine, administered once-daily, in combination with pegylated interferon alfa-2a (Pegasys) 180 _g per week: (A, n=34) pegylated interferon beginning on day 8 plus valopicitabine ramping from 400 mg to 800 mg beginning at day 29-32, followed by dosing at 800 mg; (B, n=34) valopicitabine 200 mg beginning on day 1 plus pegylated interferon beginning on day 8; (C, n=34) valopicitabine ramping from 400 mg to 800 mg from day 1-6, followed by dosing at 800 mg plus pegylated interferon beginning on day 8; (D, n=36) valopicitabine 800 mg beginning on day 1 plus pegylated interferon beginning on day 8; and (E, n=35) valopicitabine 800 mg plus pegylated interferon, both beginning on day 1.
Seventy-one percent of patients in both the valopicitabine 200 mg/day arm and the pooled valopicitabine 800 mg/day (n=105) attained HCV RNA below the limit of quantification for the Amplicor assay (<600 IU/mL) at week 24. Sixty-eight percent of patients in the valopicitabine 200 mg/day arm reached undetectable virus levels, compared to 58 percent in the pooled valopicitabine 800 mg/day arms after 24 weeks according to the TaqMan assay's lower limit of detection of 20 IU/mL.
Mean reductions of HCV RNA of 4.24 log10 after 24 weeks of treatment were achieved among patients in both the 200 mg/day dose group and the pooled 800 mg/day dosing groups.
In March 2006, the protocol for this ongoing phase IIb 48-week clinical trial in treatment naive patients was amended after GI side effects related primarily to the higher dose arms (800 mg/day) of valopicitabine were observed. The amendment required that patients in the 800 mg/day dose arms who had virus levels below 600 IU/mL, be randomized to continue study treatment with either valopicitabine 200 mg/day plus pegylated interferon or valopicitabine 400 mg/day plus pegylated interferon. Twelve percent of the treatment-naive patients did not meet the criteria and were discontinued from the trial.
Patients originally receiving the 200 mg/day dose have continued on that treatment regimen. The 24-week data discussed herein include data post protocol modifications. Through 24 weeks of treatment, 29 out of a total of 173 patients discontinued from the trial for adverse events (AEs), mostly gastrointestinal (GI) related; of these, 3 patients were from the 200 mg/day arm. Five serious adverse events (SAEs) were assessed as attributable to either valopicitabine or valopicitabine and pegylated interferon during the first 24 weeks of treatment. Most of these were GI related and four occurred in patients in an 800 mg arm. Since the dose reduction in March 2006, no valopicitabine-related GI SAEs have occurred at 200 or 400 mg arms.
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
Idenix/Novartis Collaboration
Idenix is co-promoting its hepatitis B product and developing its hepatitis B and hepatitis C product candidates, in collaboration with Novartis Pharma AG. Under this agreement, Novartis and Idenix will co-promote TYZEKA, and if successfully developed, valtorcitabine and valopicitabine, in the United States, France, Germany, Italy, Spain and the United Kingdom. Novartis has the exclusive right to commercialize licensed approved products in the rest of the world.
About Idenix
Idenix Pharmaceuticals, Inc., headquartered in Cambridge, Massachusetts, is a biopharmaceutical company engaged in the discovery, development and commercialization of drugs for the treatment of human viral and other infectious diseases. Idenix's current focus is on the treatment of infections caused by hepatitis B virus, hepatitis C virus and human immunodeficiency virus (HIV). For further information about Idenix, please refer to http://www.idenix.com.