EASL: Idenix Reports Favorable Resistance Profile for IDX719

Idenix Reports Favorable Resistance Profile for IDX719, a Potent, Pan-Genotypic HCV NS5A Inhibitor, at EASL Meeting

CAMBRIDGE, Mass., April 24, 2013 (GLOBE NEWSWIRE) -- 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 48^th 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.

www.idenix.com.