Direct-acting antiviral treatment for hepatitis C among people who use or inject drugs: a systematic review and meta-analysis

Summary Background There are concerns around poorer response to direct-acting antiviral (DAA) therapy for hepatitis C virus infection among people who use drugs. This systematic review assessed DAA treatment outcomes among people with recent drug use and those receiving opioid substitution therapy. Methods Bibliographic databases and conference presentations were searched for observational studies and clinical trials assessing DAA treatment completion, sustained virological response (SVR), and loss to follow-up among people with recent drug use (injecting or non-injecting) and those receiving opioid substitution therapy. Meta-analysis was used to pool estimates and meta-regression to explore heterogeneity. Findings 38 eligible studies, with 3634 participants, were included. The definition of recent drug use varied across studies, with drug use in the past 6 months and at the initiation of or during DAA therapy most commonly used. Among individuals with recent injecting or non-injecting drug use (21 studies; 1408 participants), treatment completion was 97·5% (95% CI 96·6–98·3) and SVR was 87·7% (95% CI 84·2–91·3). Among individuals receiving opioid substitution therapy (36 studies; 2987 participants), treatment completion was 97·4% (95% CI 96·5–98·3) and SVR was 90·7% (95% CI 88·5–93·0). Among individuals with recent injecting drug use (eight studies; 670 participants), treatment completion was 96·9% (95% CI 95·6–98·2) and SVR was 87·4% (95% CI 82·0–92·8). In meta-regression analysis, clinical trials (vs observational studies; adjusted odd ratio 2·18, 95% CI 1·27–3·75; p=0·006) and higher mean or median age (1·07, 1·02–1·12; p=0·008) were significantly associated with higher SVR. Clinical trials (0·45, 0·22–0·94; p=0·033) and older age (0·94, 0·88–0·99; p=0·034) were also significantly associated with a lower proportion of participants lost to follow-up. Interpretation Response to DAA therapy was favourable among people with recent drug use (including those who inject) and those receiving opioid substitution therapy, supporting broadening access in these populations. Funding The Kirby Institute, UNSW Sydney, and National Health and Medical Research Council of Australia.