Achillion Pharmaceuticals, Inc. has completed enrollment in a pilot Phase 2a trial evaluating ACH-3102, a second-generation pan-genotypic NS5A inhibitor, in combination with ribavirin for the treatment of patients with chronic genotype 1b (GT 1b) hepatitis C virus (HCV) infection. The initial cohort enrolled eight patients with GT 1b HCV, IL28b genotype CC, that are receiving twelve weeks of ACH-3102 once daily in combination with ribavirin. To date, five patients have completed 4 weeks of treatment, including three patients who have completed 12 weeks of treatment.

ACH-3102 has been well-tolerated by all patients with no serious adverse events, subject withdrawals, or on-treatment viral breakthrough reported to date. Treatment with ACH-3102 has resulted in rapid reduction in HCV RNA accompanied by normalization of liver enzymes. Achillion initiated in September 2012 patient enrollment into this open-label Phase 2a pilot trial evaluating 12 weeks of once daily dosing of ACH-3102 in combination with ribavirin for the treatment of chronic HCV GT 1b infection.

The study has enrolled 8 treatment-na ve patients with HCV GT 1b IL28B CC genotype. Patients received 225 mg of ACH-3102 on day 1 followed by 75 mg of ACH-3102 once daily on subsequent days in combination with 1000-1200 mg dose of ribavirin. The primary objective of the trial is to determine the safety of this dosing regimen, and the sustained virologic response 12 weeks after the completion of treatment (SVR12) with secondary endpoints assessing pharmacokinetics, pharmacodynamics, and other virologic endpoints including rapid virologic response (RVR) and end of treatment response (ETR).

To date, following up to 12 weeks of treatment with ACH-3102 in combination with ribavirin, there have been no reported serious adverse events, no treatment discontinuations and no clinically significant changes in vital signs, electrocardiograms (ECGs), or laboratory evaluations with the exception of one subject with an anemia requiring a ribavirin dose reduction.