Ritonavir-boosted danoprevir plus peginterferon alfa-2a and ribavirin in Asian chronic hepatitis C patients with or without cirrhosis.

BACKGROUND AND AIM: Chronic hepatitis C is an important public health problem in Asia. We evaluated the safety, efficacy, and pharmacokinetics of fixed-dose ritonavir-boosted danoprevir plus peginterferon alfa-2a/ribavirin in treatment-naive Asian patients with chronic hepatitis C virus (HCV) genotype (G)1 infection. METHODS: Treatment-naive G1 patients in Taiwan, Thailand, and Korea with serum HCV-RNA level ≥ 105 IU/mL received ritonavir-boosted danoprevir 125/100 mg twice daily plus peginterferon alfa-2a/ribavirin for either 12 (noncirrhotic patients: Arm A, n = 34) or 24 weeks (cirrhotic patients: Arm B, n = 27) in this phase II open-label study. Sustained virologic response was defined as HCV-RNA < 25 IU/mL 12 weeks after end of treatment (SVR12). RESULTS: Similar SVR12 rates were achieved in Arms A (88.2%; 95% confidence interval, 73.4-95.3%) and B (88.9%; 71.9-96.2%). Most patients had G1b infection, among whom SVR12 rates in Arms A and B were 96.7% and 91.7%, respectively. The overall SVR12 rate was 94.0% in noncirrhotic Taiwanese patients (100% in the subset of G1b patients). No patients withdrew for safety reasons. Three (11%) cirrhotic patients (Arm B) experienced serious adverse events, none of which was considered to be related to treatment. No Grade 3/4 alanine aminotransferase elevations were reported. The pharmacokinetic properties of danoprevir were broadly overlapping in noncirrhotic and cirrhotic patients both on Days 1 and 14. CONCLUSIONS: Ritonavir-boosted danoprevir plus peginterferon alfa-2a/ribavirin produced sustained virologic response rates > 90% after 12 weeks' treatment in noncirrhotic and 24 weeks' treatment in cirrhotic Asian patients with G1b infection and was well tolerated. These regimens are well suited to countries where G1b predominates.

Balapiravir plus peginterferon alfa-2a (40KD)/ribavirin in a randomized trial of hepatitis C genotype 1 patients.

INTRODUCTION: Balapiravir (R1626, RG1626) is the prodrug of a nucleoside analogue inhibitor of the hepatitis C virus (HCV) RNA-dependent RNA polymerase (R1479, RG1479). This phase 2, double-blind international trial evaluated the optimal treatment regimen of balapiravir plus peginterferon alfa-2a (40KD)/ribavirin. MATERIAL AND METHODS: Treatment-naive genotype 1 patients (N = 516) were randomized to one of seven treatment groups in which they received balapiravir 500, 1,000, or 1,500 mg twice daily, peginterferon alfa-2a (40KD) 180 or 90 µg/week and ribavirin 1,000/1,200 mg/day or peginterferon alfa-2a (40KD)/ribavirin. The planned treatment duration with balapiravir was reduced from 24 to 12 weeks due to safety concerns. RESULTS: The percentage of patients with undetectable HCV RNA was consistently higher in all balapiravir groups from week 2 to 12. However, high rates of dose modifications and discontinuations of one/all study drugs compromised the efficacy assessment and resulted in similar sustained virological response rates in the balapiravir groups (range 32-50%) and the peginterferon alfa-2a (40KD)/ribavirin group (43%). Balapiravir was discontinued for safety reasons in 28-36% of patients (most often for lymphopenia) and the percentage of patients with serious adverse events (especially hematological, infection, ocular events) was dose related. Serious hematological adverse events (particularly neutropenia, lymphopenia) were more common in balapiravir recipients. Two deaths in the balapiravir/peginterferon alfa-2a/ribavirin combination groups were considered possibly related to study medication. CONCLUSION: Further development of balapiravir for the treatment of chronic hepatitis C has been halted because of the unacceptable benefit to risk ratio revealed in this study (www.ClinicalTrials.gov NCT 00517439).

R1626 plus peginterferon Alfa-2a provides potent suppression of hepatitis C virus RNA and significant antiviral synergy in combination with ribavirin.

UNLABELLED: R1626, a prodrug of the hepatitis C virus (HCV) RNA polymerase inhibitor R1479, showed time-dependent and dose-dependent reduction of HCV RNA levels in a previous study. The present study evaluated the efficacy and safety of R1626 administered for 4 weeks in combination with peginterferon alfa-2a +/- ribavirin in HCV genotype 1-infected treatment-naive patients. Patients were randomized to: DUAL 1500 (1500 mg R1626 twice daily [bid] + peginterferon alfa-2a; n = 21); DUAL 3000 (3000 mg R1626 bid + peginterferon alfa-2a; n = 32); TRIPLE 1500 (1500 mg R1626 bid + peginterferon alfa-2a + ribavirin; n = 31); or standard of care (SOC) (peginterferon alfa-2a + ribavirin; n = 20). At 4 weeks HCV RNA was undetectable (<15 IU/mL) in 29%, 69%, and 74% of patients in the DUAL 1500, DUAL 3000, and TRIPLE 1500 arms, respectively, compared with 5% of patients receiving SOC, with respective mean reductions in HCV RNA from baseline to week 4 of 3.6, 4.5, 5.2, and 2.4 log(10) IU/mL. Synergy was observed between R1626 and peginterferon alfa-2a and between R1626 and ribavirin. There was no evidence of development of viral resistance. Adverse events (AEs) were mainly mild or moderate; seven patients had nine serious AEs (including one patient with one serious AE in SOC). The incidence of Grade 4 neutropenia was 48%, 78%, 39%, and 10% in DUAL 1500, DUAL 3000, TRIPLE 1500, and SOC, respectively, and was the main reason for dose reductions. CONCLUSION: A synergistic antiviral effect was observed when R1626 was combined with peginterferon alfa-2a +/- ribavirin; up to 74% of patients had undetectable HCV RNA at week 4. Dosing of R1626 was limited by neutropenia; a study of different dosages of R1626 in combination with peginterferon alfa-2a and ribavirin is underway.