CAMBRIDGE, Mass., April 24, 2013 (GLOBE NEWSWIRE) -- Idenix Pharmaceuticals, Inc. (Nasdaq: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 log 10 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 log 10 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.