Nearly all patients with chronic hepatitis C treated with an interferon-free drug regimen for 12 or 24 weeks experienced sustained virologic response in a study presented at the International Liver Congress in Amsterdam.
Researchers administered 100-200 mg HCV protease inhibitor ABT-450 (AbbVie) with 100 mg ritonavir (ABT-450/r) once daily to patients with chronic hepatitis C genotype 1, along with 25 mg NS5A inhibitor ABT-267 once daily and 400 mg non-nucleoside NS5B inhibitor ABT-333 twice a day, and weight-based ribavirin, for 12 or 24 weeks. The cohort included 79 12-week and 80 24-week recipients among treatment-naive patients, and 45 12-week and 43 24-week recipients among previous nonresponders. Patients were either treatment-naive or nonresponsive to prior pegylated interferon/ribavirin therapy.
Sustained virologic response (SVR) rates at 4 weeks among treatment-naive participants were 98.7% in the 12-week and 96.2% in the 24-week group. Among prior nonresponders, SVR4 rates were 93.3% in the 12-week and 97.7% in the 24-week groups.
Among treatment-naive patients, SVR12 was 99% in the 12-week and 93% in the 24-week group, while nonresponders experienced SVR12 in 93% of 12-week and 98% of 24-week cases. SVR24 was achieved by 96% of 12-week and 90% of 24-week treatment-naive participants and 93% of 12-week and 95% of 24-week nonresponders. Across the cohort, SVR was similar regardless of IL28B genotype, baseline HCV RNA levels, fibrosis stage and infection with HCV genotype 1a compared with 1b.
Commonly reported events included headache, fatigue, insomnia, diarrhea and nausea. Four patients withdrew from the study after experiencing serious adverse events.
“The consistency of high sustained viral response rates that we have seen in clinical trials across populations is encouraging, especially given the proportion of patients with these characteristics who have failed with interferon plus ribavirin treatment,” researcher KrisV. Kowdley, MD, director of research at the Digestive Disease Institute at Virginia Mason Medical Center in Seattle, said in a press release.
Phase 3 trials are under way for the 12-week regimen.
For more information:
Kowdley KV. #3: Safety and Efficacy of Interferon-Free Regimens of ABT-450/R, ABT-267, ABT333 ± Ribavirin in Patients With Chronic HCV GT1 Infection: Results From the Aviator Study. Presented at: The International Liver Congress 2013; April 24-28, Amsterdam.