Excellent hepatitis C virus cure rates despite increasing complexity of people who use drugs: Integrated-Test-stage Treat study final outcomes

Achieving hepatitic C virus (HCV) elimination requires linking people who use drugs (PWUD) into care. We report final direct-acting antivirals (DAAs)-based outcomes from the Integrated-Test-stage -Treat (ITTREAT) study. Project ITTREAT (2013-2021), based at an addiction centre, was a 'one-stop' service with innovative linkage to care strategies. Primary outcome was sustained virological response (SVR12) (intention to treat ITT) including whether individuals were recruited in first (period 1) versus last four (period 2 included the COVID-19 pandemic) years of the study. Number recruited were n = 765, mean age 40.9 +/- 10.1 years, 78% males, history of current/past injecting drug use (IDU) and alcohol use being 77% and 90%, respectively. Prevalence of a positive HCV PCR was 84% with 19% having cirrhosis. Comparing those recruited in period 2 versus period 1, there was increasing prevalence of IDU, 90% versus 72% (p < .001); homelessness, 67% versus 50% (p < .001); psychiatric diagnosis, 84% versus 50% (p < .001); overdose history 71% versus 31% (p < .001), receiving opioid agonist treatment (OAT) 75% versus 52% (p < .001) and comorbidity 44% versus 25% (p < .001). Of those treated with DAAs (n = 272), ITT SVR rates were 86% (95% CI: 81%-90%), being similar in period 2 versus period 1. Predictors of non-SVR were receiving OAT (OR 0.33, 95% CI: 0.12-0.87, p = .025) and >= 80% adherence (OR 0.01, 95% CI: 0.003-0.041, p < .001). Reinfection rates period 2 versus period 1 (per 100 person-years) were 1.84 versus 1.70, respectively. In the treated cohort, mortality was 15%, being mostly drug-related. Despite increasing complexity of PWUD, high SVR12 rates are achievable with use of OAT and good adherence.