IDDF2018-ABS-0067 Efficacy and safety of glecaprevir/pibrentasvir in patients with hcv genotype 5 or 6 infection: the endurance-5, 6 study

Background The pangenotypic direct-acting antivirals (DAAs) glecaprevir (developed by AbbVie and Enanta)/pibrentasvir (G/P) are approved to treat chronic HCV genotype (GT)1–6 infection. In Phase 2 and 3 studies, G/P achieved high SVR12 rates with no virologic failures in 80 patients with GT5 or 6 infection. To increase the body of data for these genotypes, ENDURANCE-5,6 evaluates patients from countries where GT5 and GT6 are endemic, such as South Africa (GT5), Myanmar and Vietnam (GT6). This study evaluates the efficacy and safety of G/P in patients with chronic HCV GT5 or GT6 infection. Methods ENDURANCE-5,6 is an ongoing phase 3b, non-randomised, open-label, multicenter study conducted in adults with chronic HCV GT 5 or 6 infections with or without compensated cirrhosis who are HCV treatment-naive or experienced with interferon (IFN) or pegIFN with or without ribavirin (RBV) or sofosbuvir and RBV with or without pegIFN. G/P (300 mg/120 mg) was orally dosed once-daily for 8 or 12 weeks in patients without or with compensated cirrhosis, respectively. The primary efficacy endpoint was SVR12. Secondary endpoints were on-treatment virologic failure or relapse. Adverse events and clinical laboratory abnormalities were monitored in all patients. Results Seventy patients have enrolled to date, 61 and 9 in the 8- and 12 week treatment arms, respectively; 66 have completed treatment. Baseline demographics are shown in table 1. The SVR4 among patients with available data is 61/62 (98%). One HCV GT6c-l-infected patient with compensated cirrhosis experienced virologic breakthrough at treatment week 12, and one HCV GT5a-infected patient without compensated cirrhosis who achieved SVR4 relapsed at post-treatment week 12. To date, three patients (4%) have experienced treatment-emergent serious adverse events, none of which were related to G/P or led to discontinuation; no Grade 3 alanine aminotransferase elevations have occurred. Conclusions In this ongoing dedicated study, HCV genotype 5- and 6-infected patients without and with compensated cirrhosis treated with G/P for 8 and 12 weeks, respectively, achieved high rates of SVR4. Complete SVR4 and available SVR12 data will be presented.