Research ArticleSimeprevir with peginterferon/ribavirin for treatment-naïve hepatitis C genotype 1 patients in Japan: CONCERTO-1, a phase III trial

Background & AimsIn a Japanese Phase II study, the hepatitis C virus NS3/4A protease inhibitor simeprevir demonstrated potent antiviral activity and significantly improved sustained virologic response rates when added to peginterferon α-2a/ribavirin in treatment-naïve patients infected with hepatitis C virus genotype 1.MethodsCONCERTO-1 was a Phase III, randomized, double-blind, placebo-controlled trial. Treatment-naïve adults (⩽70 years) with chronic hepatitis C virus genotype 1 infection (hepatitis C virus RNA ⩾5 log10 IU/ml) were randomized (2:1) to simeprevir 100 mg once-daily with peginterferon α-2a/ribavirin for 12 weeks then response-guided therapy with peginterferon α-2a/ribavirin for 12 or 36 weeks, or to placebo with peginterferon α-2a/ribavirin for 12 weeks then peginterferon α-2a/ribavirin for 36 weeks.ResultsOverall, 183 patients were treated. Sustained virologic response 12 weeks after treatment end (primary efficacy endpoint) was achieved in 88.6% of simeprevir- and 61.7% of placebo-treated patients (p <0.0001 for stratum-adjusted between-group difference). Overall, 91.9% of simeprevir-treated patients met response-guided therapy criteria and completed treatment at week 24; sustained virologic response rate at 12 weeks in these patients was 92.0%. One simeprevir- (0.8%) and two placebo-treated patients (3.3%) experienced viral breakthrough; respective viral relapse rates were 7.6% and 30.6%. Overall adverse event profile in simeprevir-treated patients was comparable to that in patients who received peginterferon α-2a/ribavirin alone.ConclusionsSimeprevir once daily with peginterferon α-2a/ribavirin significantly improved sustained virologic response rate 12 weeks after treatment end in treatment-naïve patients with chronic hepatitis C virus genotype 1 infection, with a shorter 24-week treatment duration in most patients.