AbbVie, Enanta Show HCV Results

Enanta Pharmaceuticals has posted results from the SAPPHIRE-I study, one of six Phase III studies being conducted by AbbVie for the treatment of hepatitis C virus (HCV) genotype 1 (GT1) infection, using a regimen containing Enanta’s lead protease inhibitor ABT-450.

ABT-450 is part of AbbVie’s investigational three direct-acting antiviral (3D) regimen, consisting of boosted protease inhibitor ABT-450/ritonavir, NS5A inhibitor ABT-267, and non-nucleoside polymerase inhibitor ABT-333. The SAPPHIRE-I study used this 3D regimen plus ribavirin.

Results from the 631-patient trial demonstrated a sustained virologic response at 12 weeks post-treatment (SVR12) of 96% in treatment-naïve adult patients chronically infected with GT1 HCV. The majority of patients were GT1a, considered the more difficult-to-treat subtype, and the SVR12 rates of GT1a and GT1b were 95% and 98%, respectively. These results were based on an intent-to-treat analysis and were achieved after 12 weeks of treatment. The rate of virologic relapse or breakthrough was low, occurring in 1.7% of patients receiving the 3D regimen. The treatment regimen was well tolerated, with an equal percentage of patients in the active and placebo arms discontinuing treatment due to adverse events.

SAPPHIRE-I was a global, multi-center, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of 12 weeks of treatment with ABT-333 (250mg), ribavirin (weight-based), both dosed twice daily, and the fixed-dose combination of ABT-450/ritonavir (150/100mg) co-formulated with ABT-267 (25mg) and dosed once daily in non-cirrhotic, GT1a and GT1b HCV-infected, treatment-naïve adult patients.

AbbVie has announced that results from the remaining five ABT-450-containing studies in its Phase III program will be available in the coming months, supporting regulatory submissions starting in 2Q14.