Su1053 Virological Response in Treatment-Naïve Patients With Chronic HCV Genotype-1 Infection Receiving Faldaprevir Plus Pegylated Interferon α-2A and Ribavirin Is Unaffected by Ribavirin Dose Reduction

Background: Optimal duration of interferon-free HCV treatment continues to be examined in clinical trials. The SOUND-C2 and -C3 studies assessed the efficacy and safety of 16, 24, 28 and 40 weeks (W) of the interferon-free combination of faldaprevir, deleobuvir ± ribavirin in treatment-naive patients infected with HCV genotype (GT)-1. Relapse was higher in HCV GT-1a-infected patients treated for 16W with this regimen compared with GT-1b. We examined the relationship between duration of undetectable HCV RNA and virological response in SOUND-C2 and -C3. Methods: Patients received faldaprevir 120 mg QD plus deleobuvir 600 mg BID or TID. A ribavirin-free arm was investigated in SOUND-C2. The relationship between duration of undetectable HCV RNA to the end of treatment and SVR12 was assessed. Results: SVR rates among patients with undetectable HCV RNA at the last ontreatment visit, based on duration of undetectable HCV RNA, are shown (Table). GT-1binfected patients may require less time at undetectable HCV RNA (8-12W) compared with GT-1a patients (>16W) in order to achieve SVR. Regression analysis indicated that duration of undetectable HCV RNA was significantly associated with SVR. Conclusions: Duration of undetectable HCV RNA to end of treatment with this two DAA regimen was associated with SVR. These data suggest that the optimal treatment duration in GT-1b-infected patients is between 8W and 12W plus the time required to reach undetectable HCV RNA. There were