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

Background: 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.
Methods: 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).
Results: 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%).
Conclusion: 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).