Oral, Interferon-Free Hepatitis C Vaccine Shows Promise in Phase III Trial
Treatment helps 96% of patients (November 18)
Positive phase III results have been reported for an investigational three direct-acting–antiviral (3D) regimen (AbbVie Inc.) plus ribavirin in patients chronically infected with genotype 1 (GT1) hepatitis C virus (HCV).
The 3D regimen consists of a boosted protease inhibitor (ABT-450) plus ritonavir (Norvir, AbbVie); a non-structural 5A (NS5A) protein inhibitor (ABT-267); and a non-nucleoside polymerase inhibitor (ABT-333).
In the 631-patient SAPPHIRE-I trial, patients new to therapy receiving 12 weeks of the 3D regimen achieved a sustained virologic response at 12 weeks post-treatment (SVR12) of 96% (455/473). Most of the patients had GT1a HCV infection (considered to be the more difficult-to-treat subtype), and the SVR12 rates of GT1a and GT1b were 95% (307/322) and 98% (148/151), respectively. The rate of virologic relapse or breakthrough was low, occurring in 1.7% of patients receiving the 3D regimen. In addition, discontinuation rates due to adverse events were low and of an equal percentage (0.6%) in both the active and placebo groups.
SAPPHIRE-I was a global, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of 12 weeks of treatment with ABT-333 (250 mg), ribavirin (weight-based), both dosed twice daily, and a fixed-dose combination of ABT-450/ritonavir (150 mg/100 mg) co-formulated with ABT-267 (25 mg) and dosed once daily in non-cirrhotic, GT1a and GT1b HCV-infected, treatment-naïve adult patients.
The study population consisted of 631 GT1 treatment-naïve patients with no evidence of liver cirrhosis. A total of 473 patients were randomly assigned to receive the 3D regimen plus ribavirin for 12 weeks, and 158 patients were given placebo for the initial 12 weeks. Patients who were randomly assigned to receive placebo for the first 12 weeks then received open-label treatment with the 3D regimen plus ribavirin for 12 weeks.
Source: AbbVie Inc.; November 18, 2013.