Multi-Drug Hepatitis C Regimen Meets Phase III Endpoints
Sustained virologic response achieved in 99% of patients
Results from a pivotal phase III study of an investigational multi-drug regimen for hepatitis C virus (HCV) infection, developed by AbbVie, were presented March 4 at the 21st Conference on Retroviruses and Opportunistic Infections, held in Boston.
The PEARL-III trial evaluated the efficacy and safety of 12 weeks of treatment with the investigational therapy, with or without ribavirin, in 419 treatment-naïve, non-cirrhotic adult patients with chronic genotype 1b (GT1b) HCV infection.
The trial met its primary and secondary endpoints. Sustained virologic response rates at 12 weeks post-treatment (SVR12) of 99.5% and 99.0% were achieved with the investigational regimen with and without ribavirin, respectively. There were no treatment discontinuations due to adverse events.
The investigational regimen consists of a fixed-dose combination of ABT-450/ritonavir (150/100 mg) co-formulated with ABT-267 (25 mg), dosed once daily, and ABT-333 (250 mg) with or without ribavirin (weight-based), dosed twice daily. The combination of three different mechanisms of action interrupts the HCV replication process, with the goal of optimizing SVR rates across different patient populations, according to the manufacturer.
The global, randomized, double-blind, placebo-controlled study enrolled 419 GT1b treatment-naive patients with no evidence of liver cirrhosis: 209 patients were randomly assigned to the investigational regimen without ribavirin, and 210 patients were randomly assigned to the investigational regimen with ribavirin. After 12 weeks of treatment, 99.0% of the patients receiving the investigational regimen without ribavirin (n = 207/209) and 99.5% of the patients receiving the investigational regimen with ribavirin (n = 209/210) achieved SVR12. Patients in the treatment arm without ribavirin received placebo in substitution for ribavirin.
Across treatment arms, there were no documented relapses within 12 weeks after treatment. No on-treatment virologic failures occurred in the treatment arm without ribavirin, and a single virologic failure occurred in the treatment arm with ribavirin.
The most commonly reported adverse events (greater than 10% for either arm) were headache, fatigue, pruritus, nausea, and asthenia. Pruritus and nausea occurred at a significantly higher rate in the treatment arm with ribavirin compared with the arm without ribavirin. Anemia occurred more commonly among patients in the ribavirin-containing arm, with clinically significant anemia requiring ribavirin dose reductions in 9% of these patients.
Neither ribavirin nor ritonavir is currently approved for the treatment of HCV infection.
Source: AbbVie; March 3, 2014.