CAMBRIDGE, MA, USA I April 24, 2013 I Idenix Pharmaceuticals, Inc. (IDIX), a biopharmaceutical company engaged in the discovery and development of drugs for the treatment of human viral diseases, today reported detailed resistance data from in vitro studies and from a three-day monotherapy clinical trial of IDX719, the Company’s once-daily, potent, pan-genotypic NS5A inhibitor for the treatment of hepatitis C virus (HCV) infection. These data are being presented on Saturday, April 27, in a poster session at the 48th Annual Meeting of the European Association for the Study of the Liver (EASL), which is being held April 24 – 28, 2013 in Amsterdam, The Netherlands.

Data from the three-day proof-of-concept study demonstrated that IDX719 was well-tolerated at daily doses up to 100 mg and showed potent antiviral activity across HCV genotypes 1-4, with mean maximal viral load reductions up to approximately 4.0 log10 IU/mL. These data were supported by earlier in vitro findings. Clinical plasma samples at baseline, at end of treatment and at one week post-treatment were sequenced for mutations in NS5A at known IDX719 resistance-associated locations.

  • The most common treatment-emergent resistant mutations were detected at NS5A positions 28, 31 and 93. The profile of these mutations varied among genotypes.
  • The only resistance mutation present at baseline found to negatively affect IDX719 response was M31 in GT2-infected patients. In contrast, all GT4-infected patients had virus with M31 at baseline and responded favorably to IDX719 treatment.
  • A GT1b-infected patient with a baseline Y93H mutation, which confers in vitro resistance to IDX719, achieved a 2.79 log10 IU/mL viral load reduction after three days of once-daily 25 mg IDX719, indicating that IDX719 can retain activity against virus with known resistance mutations.

The poster presentation is titled, “Treatment-Emergent Variants Following 3 Days of Monotherapy with IDX719, a Potent, Pan-Genotypic NS5A Inhibitor, in Subjects Infected with HCV Genotypes 1-4″ (Abstract No. 1209).

“These additional resistance data support the promising profile of IDX719 as a potent, pan-genotypic component of future HCV combination treatment regimens,” commented Douglas Mayers, M.D., Chief Medical Officer of Idenix. “We look forward to evaluating IDX719 as part of all-oral combination therapies through our collaboration with Janssen, beginning with the initiation of a phase II clinical trial of IDX719 and simeprevir in the first half of this year.”

ABOUT IDX719

IDX719 is an NS5A inhibitor with low picomolar, pan-genotypic antiviral activity in vitro. To date, IDX719 has been safe and well tolerated after single and multiple doses of up to 100 mg in healthy volunteers (n=36; up to 7 days duration) and HCV-infected patients (n=69; up to 3 days duration). There have been no treatment-emergent serious adverse events reported in the program. IDX719 has demonstrated potent pan-genotypic antiviral activity in HCV-infected patients with mean maximal viral load reductions up to approximately 4.0 log10 IU/mL across HCV genotypes 1-4 in a proof-of-concept, three-day monotherapy study.

ABOUT HEPATITIS C

Hepatitis C virus is a common blood-borne pathogen infecting three to four million people worldwide annually. The World Health Organization (WHO) estimates that more than 170 million people worldwide are chronically infected with HCV, representing a nearly 5-fold greater prevalence than human immunodeficiency virus.

ABOUT IDENIX

Idenix Pharmaceuticals, Inc., headquartered in Cambridge, Massachusetts, is a biopharmaceutical Company engaged in the discovery and development of drugs for the treatment of human viral diseases. Idenix’s current focus is on the treatment of patients with HCV. For further information about Idenix, please refer to www.idenix.com.

SOURCE: Idenix Pharmaceuticals