Efficacy and Safety of Danoprevir/Ritonavir plus Peginterferon Alfa-2a/Ribavirin in HCV Genotype 1 Prior Null Responders

Antimicrob Agents Chemother. 2013 Dec 2. [Epub ahead of print]

Gane EJ, Rouzier R, Wiercinska-Drapalo A, Larrey DG, Morcos PN, Brennan BJ, Le Pogam S, Nájera I, Petric R, Tran JQ, Kulkarni R, Zhang Y, Smith P,Yetzer ES, Shulman NS.

Auckland Clinical Studies, Auckland, New Zealand.

Abstract

Background & Aims: Danoprevir (DNV) is a hepatitis C virus (HCV) protease inhibitor that achieves high sustained virologic response (SVR) rates in combination with peginterferon alfa-2a/ribavirin in treatment-naive HCV genotype (G)1-infected patients. This study explored the efficacy and safety of ritonavir-boosted DNV (DNVr) plus peginterferon alfa-2a/ribavirin in G1 prior peginterferon/ribavirin null responders.Methods: Null responders (<2-log₁₀ reduction in HCV RNA at week 12) were given open-label DNVr 100/100 mg q12h + peginterferon alfa-2a/ribavirin for 12 weeks. All patients achieving an early virologic response (EVR; ≥2-log₁₀ decrease in HCV RNA by week 12) continued treatment with peginterferon alfa-2a/ribavirin; those without an EVR discontinued all study drugs.Results: Twenty-four prior null responders were enrolled; 16 patients (67%) were infected with HCV G1b, and 8 (33%) with G1a. 96% of patients had an IL28B non-CC genotype. An SVR24 was achieved in 67% of patients, with a higher rate in G1b-infected (88%) vs. G1a-infected (25%) patients. Resistance-related breakthrough occurred in 4/8 G1a and 1/16 G1b patients through the DNV resistance-associated variant (RAV) NS3 R155K. NS3 R155K was also detected in 2/2 G1a patients who relapsed. Treatment was well tolerated. Two patients withdrew prematurely from study medications due to adverse events. Two serious adverse events were reported; both occurred after completion of DNVr therapy and were considered unrelated to treatment. No Grade 3/4 ALT elevations were observed.Conclusions: DNVr plus peginterferon alfa-2a/ribavirin demonstrated high SVR24 rates in HCV G1b prior null responders and was well tolerated.

PMID: 24295986 [PubMed - as supplied by publisher]

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