[mtwalsh01]

Enanta Pharmaceuticals, Inc. (ENTA) have announced positive new results from the phase III SAPPHIRE-I study being conducted by AbbVie for hepatitis C virus (HCV) genotype 1 (GT1) treatment. The trial tested Enanta’s lead protease inhibitor ABT-450 in a 3D regimen comprising three direct-acting anti-viral agents, i.e. boosted protease inhibitor ABT-450/ritonavir, NS5A inhibitor ABT-267, and non-nucleoside polymerase inhibitor ABT-333. This study, along with five other hepatitis C virus (HCV) genotype 1 (GT1) phase III studies being conducted by AbbVie, is addressing the need to develop interferon-free treatment regimens for hepatitis C virus (HCV) infection, as discussed previously on this forum (http://www.biotechnologyforums.com/thread-2564.html). This is because some patients are interferon-intolerant, and so interferon-based therapy for chronic hepatitis C is limited by both efficacy and tolerability.

In the SAPPHIRE-I study, the 3D regimen plus ribavirin was used. 631 non-cirrhotic, GT1a and GT1b HCV-infected, treatment-naïve adult patients were enrolled in this global, multi-centre, randomised, double-blind, placebo-controlled study for 12 weeks of treatment. The majority of patients were GT1a, the more difficult-to-treat subtype. The results indicated that a sustained virologic response after 12 weeks (SVR12) was achieved for 96% of patients. There was a low rate of relapse (1.7% of patients on the 3D regimen). The treatment regimen was well tolerated, with the most commonly reported adverse events being fatigue, headache and nausea and discontinuation of treatment occurred in equal percentages (0.6%) in both the placebo and 3D groups. This positive phase III data follows on from previous positive phase II studies on tolerability and efficacy of ABT-450 in various combination treatment regimes. Results of the remaining five phase III trials using ABT-450 will be available in the coming months, with regulatory submissions to begin in the second quarter of 2014.These current findings raise hopes that pegylated interferon-free regimens have the potential to cure a high proportion of HCV genotype 1-infected patients.

Sources
http://www.biospace.com/News/abbvie-enan...s-c/316030 [Accessed 19 November 2013].

LAWITZ, E. et al., 2013. A phase 2a trial of 12-week interferon-free therapy with two direct-acting antivirals (ABT-450/r, ABT-072) and ribavirin in IL28B C/C patients with chronic hepatitis C genotype 1. Journal of Hepatology, 59(1), pp. 18-23

POORDAD, F. et al., 2013. Exploratory study of oral combination antiviral therapy for hepatitis C. The New England Journal of Medicine, 368(1), pp. 45-53

STEDMAN, C.A.M., 2013. Current prospects for interferon-free treatment of hepatitis C in 2012. Journal of Gastroenterology and Hepatology, 28(1), pp. 38-45