Abstract
BACKGROUND: With the advent of efficacious oral direct-acting antivirals (DAAs) for hepatitis C virus (HCV), identification of characteristics associated with adherence is critical to treatment success. We examined correlates of sub-optimal adherence to HCV therapy in a single-arm, multinational, clinical trial. METHODS: ACTG A5360 enrolled HCV treatment-naive persons without decompensated cirrhosis from 5 countries. All participants received a 12-weeks course of sofosbuvir/velpatasvir at entry. In-person visits occurred at initiation and week 24, sustained virologic response (SVR) assessment. Adherence at week 4 was collected remotely and was dichotomized optimal (100%, no missed doses) versus sub-optimal (<100%). Correlates of sub-optimal adherence were explored using logistic regression. RESULTS: In total, 400 participants enrolled; 399 initiated treatment; 395/397 (99%) reported completing at week 24. Median age was 47 years with 35% female. Among the 368 reporting optimal adherence at week 4 SVR was 96.5% (95% confidence interval [CI] [94.1%, 97.9%]) vs 77.8% (95% CI [59.2%, 89.4%]) P value < .001. In the multivariate model age <30 years and being a US participant were independently associated with early sub-optimal adherence. Participants <30 years were 7.1 times more likely to have early sub-optimal adherence compared to their older counterparts. CONCLUSIONS: Self-reported optimal adherence at week 4 was associated with SVR. Early self-reported adherence could be used to identify those at higher risk of treatment failure and may benefit from additional support. Younger individuals <30 years may also be prioritized for additional adherence support. Clinical Trials Registration. NCT03512210.