Open Access

Although direct-acting antiviral medications effectively cure hepatitis C in most patients, sometimes treatment selects for resistant viruses, causing antiviral drugs to be either ineffective or only partially effective. Multidrug resistance is common in patients for whom DAA treatment fails. Older patients and patients with advanced liver diseases are more likely to select drug-resistant viruses. Collective efforts from international communities and governments are needed to develop an optimal approach to managing drug resistance and preventing the transmission of resistant viruses.

Background & Aims: Adequate adherence to hepatitis C virus (HCV) treatment is believed to be a key component of treatment success because non‐adherence can potentially result in treatment failure and the emergence of resistant viral variants. This analysis assessed factors associated with non‐adherence to glecaprevir/pibrentasvir (G/P) therapy and the impact of non‐adherence on sustained virological response at post‐treatment week 12 (SVR12) rates in HCV genotype (GT) 1‐6‐infected patients. Methods: Adherence was calculated by pill counts at study visits during treatment, and defined as having a lowest treatment adherence of ≥80% and ≤120% at each study visit. Exploratory logistic regression modelling assessed predictors of non‐adherence to G/P therapy. SVR12 rates by treatment adherence were assessed in the intent‐to‐treat (ITT) population and modified ITT (mITT) population, which excludes non‐virological failures. Results: Overall, 97% (2024/2091) of patients were adherent to G/P therapy at all consecutive study visits. Alcohol use was the only baseline characteristic independently associated with non‐adherence to G/P therapy (OR: 2.38; 95% CI: 1.13‐5.01; P = .022). In the mITT population, overall SVR12 rates were high both in patients who were adherent to G/P therapy and those who were not (99% [1983/2008] and 95% [58/61] respectively; P = .047). Corresponding SVR12 rates in the ITT population were 98% (1983/2024) and 87% (58/67) respectively. Conclusions: Most patients adhered to G/P therapy. SVR12 rates were high both in patients who were adherent to G/P treatment and those who were not. Patient education on treatment adherence should remain an important part of HCV treatment. Clinical trials registration: NCT02604017, NCT02640482, NCT02640157, NCT02636595, NCT02642432, NCT02651194, NCT02243293, NCT02446717.