Idenix Pharmaceuticals reports phase I study results of IDX184 for treating HCV

Idenix Pharmaceuticals, Inc. (Nasdaq: IDIX), a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases, today announced presentations of data on IDX184, a once-daily novel liver-targeted nucleotide prodrug of 2'-methyl guanosine (2'MeG) for the treatment of HCV, at the annual meeting of the American Association for the Study of Liver Diseases (AASLD) currently being held in Boston, Massachusetts.

Data from a three-day, phase I proof-of-concept study evaluating the safety and antiviral activity of IDX184 will be presented. This double-blind, placebo-controlled, monotherapy, dose-escalation study enrolled 41 treatment-naive HCV genotype 1-infected patients into four dosing cohorts (25 mg, 50 mg, 75 mg and 100 mg). IDX184 was well tolerated in this study with no serious adverse events reported and no discontinuations from the study. Patterns of adverse events (AEs) were similar between IDX184- and placebo-treated patients with the most frequent AEs being headache, diarrhea and dizziness. Mean viral load declines ranged from 0.47 log10 in the 25 mg group to 0.74 log10 in the 100 mg group after three days of treatment. In the 75 and 100 mg/day cohorts, patients receiving IDX184 experienced improvements in two key markers of liver injury (AST and ALT), with mean levels of these enzymes decreasing to within normal range. Pharmacokinetic data demonstrated that higher plasma levels of 2'MeG were associated with greater reductions in viral load and ALT levels.

"With favorable safety data and good antiviral activity for IDX184 in HCV patients, these early results are encouraging," said Dr. Jacob Lalezari, principal investigator in the study, Director of Quest Clinical Research and an Assistant Clinical Professor of Medicine at UCSF/Mount Zion Hospital. "Nucleotides may become an essential component of future STAT-C combinations for the treatment of hepatitis C. IDX184 has shown a promising early profile and should be evaluated in longer-term, combination trials."

Results will also be presented from in vitro studies evaluating the combination of IDX184 with other direct-acting antivirals or standard-of-care agents, interferon and ribavirin. These in vitro studies suggest that when IDX184 is combined with compounds from different classes, the antiviral activity may be enhanced, and in some combinations, synergistic. Specifically, the triple combination of IDX184, interferon and ribavirin showed strong synergy in vitro. These in vitro studies also suggest that the combination of IDX184 with other compounds from different classes may suppress the emergence of resistance.

"The in vitro combination data for IDX184 are promising," said David Standring, executive vice president of biology for Idenix. "We look forward to assessing this potential synergy in the next clinical study evaluating IDX184 in combination with pegylated interferon and ribavirin in HCV genotype 1-infected patients."