Enanta Announces Results From Four All-Oral, Interferon-Free, Phase 3 Studies

(RTTNews) - Enanta Pharmaceuticals Inc. (ENTA) announced results from the PEARL-II, PEARL-III, PEARL-IV and TURQUOISE-II studies. These studies are the remaining four phase 3 studies of the six phase 3 registrational studies being conducted by AbbVie for the treatment of genotype 1 or GT1 hepatitis C virus or HCV infection using a regimen containing Enanta's lead protease inhibitor ABT-450. ABT-450 is part of AbbVie's investigational three direct-acting antiviral regimen consisting of boosted protease inhibitor ABT-450/ritonavir, NS5A inhibitor ABT-267, and non-nucleoside polymerase inhibitor ABT-333. These studies were conducted with and without ribavirin.

The combination of the three different mechanisms of action in this regimen interrupts the HCV replication process with the goal of optimizing SVR rates across different patient populations.

Results from these studies demonstrate high sustained virologic response rates 12 weeks post treatment (SVR12) and tolerability in these GT1 patients and low rates of discontinuation due to adverse events.

Overall, across the four studies, the three direct-acting antiviral regimen was well tolerated with few adverse event-related discontinuations. The most commonly reported adverse events in PEARL-II and PEARL-III were fatigue and headache. In PEARL-IV and TURQUOISE-II, the most commonly reported adverse events were fatigue, headache and nausea.

"We are pleased that SVR rates continue to be high in both treatment-naive and treatment-experienced GT1 HCV patients with and without ribavirin, as well as in the difficult-to-treat compensated cirrhotic patients. In addition, these trials demonstrate the exceptional tolerability of the regimen, with less than one percent (0.8%) of patients discontinuing therapy due to adverse events," said Jay R. Luly, President and CEO.

"We are also pleased that AbbVie has announced it is on track to begin major regulatory submissions early in the second quarter of 2014," said Jay Luly.

These six phase 3 trials included 2,308 patients from more than 25 countries around the world. This is the only registrational program to include a dedicated study of an all-oral regimen in patients with compensated cirrhosis. In May 2013, AbbVie's three direct-acting antiviral regimen with and without ribavirin for GT1 HCV was designated as a Breakthrough Therapy by the U.S. Food and Drug Administration (FDA).

AbbVie has stated that it intends to disclose detailed study results at future scientific congresses and in publications.

AbbVie announced it expects U.S. launch in 2014.

In December 2006, Enanta and Abbott announced a worldwide agreement to collaborate on the discovery, development and commercialization of HCV NS3 and NS3/4A protease inhibitors and HCV protease inhibitor-containing drug combinations.