Short article: Faldaprevir, deleobuvir and ribavirin in IL28B non-CC patients with HCV genotype-1a infection included in the SOUND-C3 phase 2b study

Abstract

SOUND-C3 was a multicentre, open-label, phase 2b study exploring the safety and efficacy of the interferon-free combination of faldaprevir (an NS3/A4 protease inhibitor), deleobuvir (BI 207127, a non-nucleoside polymerase inhibitor) and ribavirin in treatment-naive patients with chronic hepatitis C virus (HCV) genotype-1 infection. Results in patients with HCV genotype-1b and in IL28B CC genotype patients with HCV genotype-1a have been described previously. This report describes the results in IL28B non-CC genotype patients with HCV genotype-1a. Patients were randomized to receive faldaprevir 120 mg once daily with deleobuvir at either 800 mg twice daily (b.i.d.; N=26) or 600 mg three times daily (t.i.d.; N=25), and weight-based ribavirin for 24 weeks. The primary endpoint was sustained virological response 12 weeks after treatment (SVR12). In each group, five patients completed 24 weeks of treatment. SVR12 rates were 19% (5/26) and 8% (2/25) in the b.i.d. and t.i.d. groups, respectively. On-treatment breakthrough [50% (13/26) and 68% (17/25) in the b.i.d. and t.i.d. groups, respectively] was the most frequent reason for not achieving SVR12. Adverse events led to premature treatment discontinuation in six (23%) patients in the b.i.d. group and in two patients (8%) in the t.i.d. group. The majority of adverse events were mild or moderate; the most frequently reported were nausea (67%), fatigue (35%) and diarrhoea (35%). In this small study, the interferon-free regimen of faldaprevir, deleobuvir and ribavirin resulted in high rates of virological breakthrough and low rates of SVR12 in IL28B non-CC genotype patients infected with genotype-1a HCV (http://www.clinicaltrials.gov NCT01132313).