Abbott and Enanta Pharmaceuticals have reported positive 12-week results from a Phase II study of ABT-450/r, an investigational oral protease inhibitor being developed for the treatment of hepatitis C.

The results revealed that 92% of the 24 patients receiving ABT-450/r once-daily, combined with standard of care, achieved complete early virologic response at 12 weeks.

In a separate analysis of three-day resistance data, ABT-450/r dosed at 200/100mg appeared to more consistently suppress the emergence of ABT-450-associated resistant variants than the 50/100mg and 100/100mg doses.

The 48-week Phase II study is designed to evaluate the safety, tolerability, pharmacokinetics, and antiviral activity of multiple dose strengths of ABT-450/r in treatment-naïve adults infected with hepatitis C virus genotype 1.

Trial endpoints include early virologic response and rapid virologic response.