Enanta’s lead hepatitis C compound ABT-450 advances into clinical phase 3 through its collaboration with Abbott

Date: 18/10/2012

October 17, 2012, Watertown MA, USA – Enanta Pharmaceuticals, Inc., announced that Abbott initiated an interferon-free combination Phase 3 clinical trial for hepatitis C (HCV) that included the collaboration’s protease inhibitor, ABT-450.  This trial was initiated following the release of positive results from the study known as “Aviator”, a Phase 2b trial designed and conducted by Abbott.  The initiation of this Phase 3 trial, part of Abbott’s global registration program, triggered a collaboration milestone payment to Enanta.

The focus of ABT-450 development is to study the compound in combination with other antiviral agents in Abbott’s HCV portfolio.  The three direct acting antivirals, or triple DAA cocktail, studied in the Phase 2b interferon-free Aviator trial included ritonavir-boosted protease inhibitor ABT-450/r, non-nucleoside polymerase inhibitor ABT-333, and NS5A inhibitor ABT-267.

Initial results from the Aviator trial show sustained virological response at 12 weeks post-treatment (SVR12) in 99 percent of treatment-naive (n=77), and 93 percent of null-responders (n=41), genotype 1 (GT1) HCV patients taking a combination of ABT-450 with ritonavir (ABT-450/r), ABT-267, ABT-333 and ribavirin for 12 weeks, based on an observed data analysis.

“The high SVR12 rates achieved in the genotype 1-infected population and the tough-to-treat IL28B non-CC genotype patient populations are very encouraging,” commented Jay Luly, Ph.D., President and CEO of Enanta.  “We look forward to the Phase 3 development of this interferon-free, oral treatment regimen containing our collaboration’s HCV protease inhibitor, ABT-450.”

Full results from the study will be presented at the Latebreaker Session during the 63rd Annual Meeting of the American Association for the Study of Liver Diseases (AASLD), November 9-13, 2012, in Boston.  Abstracts can be viewed on the AASLD website at

The observed data analysis used in this abstract does not include six patients who had not yet reached post-treatment week 12 or had missing values (data points) at the time of the abstract submission.  All virologic failures and safety discontinuations were included in the analysis.