An integrated analysis of elbasvir/grazoprevir in Korean patients with hepatitis C virus genotype 1b infection

BACKGROUND/AIMS: In the Republic of Korea, an estimated 231,000 individuals have chronic hepatitis C virus (HCV) infection. The aim of the present analysis was to evaluate the safety and efficacy of elbasvir/grazoprevir (EBR/GZR) administered for 12 weeks in Korean patients who were enrolled in international clinical trial phase 3 studies. METHODS: This was a retrospective, integrated analysis of data from patients with HCV genotype (GT) 1b infection enrolled at Korean study sites in four EBR/GZR phase 3 clinical trials. Patients were treatment-naive or had previously failed interferon-based HCV therapy, and included those with human immunodeficiency virus coinfection or Child-Pugh class A cirrhosis. All patients received EBR 50 mg/GZR 100 mg once daily for 12 weeks. The primary endpoint was sustained virologic response at 12 weeks after completion of therapy (SVR12, HCV RNA <15 IU/mL). RESULTS: SVR12 was achieved by 73 of 74 (98.6%) patients. No patients had virologic failure and one discontinued from the study after withdrawing consent. SVR12 rates were uniformly high across all patient subgroups. A total of 16 patients had nonstructural protein 5A resistance-associated substitutions at baseline (16/73, 22%), all of whom achieved SVR12. Adverse events (AEs) reported in >5% of patients were fatigue (6.8%), upper respiratory tract infection (5.4%), headache (5.4%), and nausea (5.4%). Thirteen patients (17.6%) reported drug-related AEs, two serious AEs occurred, and two patients discontinued treatment owing to an AEs. CONCLUSIONS: In this retrospective analysis, EBR/GZR administered for 12 weeks was well-tolerated and highly effective in Korean patients with HCV GT1b infection.