Directly observed therapy at opioid substitution facilities using sofosbuvir/velpatasvir results in excellent SVR12 rates in PWIDs at high risk for non-adherence to DAA therapy

Background & aims We evaluated the effectiveness of sofosbuvir/velpatasvir (SOF/VEL) in difficult-to-treat PWIDs with presumed high risk for non-adherence to antiviral therapy using an innovative concept involving their opioid agonist therapy (OAT) facility. Methods N = 221 patients (m/f: 168/53; median age: 44.7 years (IQR 16.9); HCV-genotype 3: 45.2%; cirrhosis: 33.9%) treated with SOF/VEL were included. PWIDs at high risk for non-adherence to DAA therapy (n = 122) received HCV treatment alongside OAT under the supervision of medical staff ("directly observed therapy", DOT). These patients were compared to patients with presumed excellent drug compliance, who were treated in a "standard setting" (SS) of SOF/VEL prescription at a tertiary care center (n = 99). Results DOT-patients (n = 122/221; 55.2%) were younger than SS-patients (median age: 41.3 vs. 53.0 years), all had psychiatric comorbidities and most had a poor socioeconomic status. 83/122 (68.0%) reported ongoing intravenous drug use. Within the DOT-group, SVR12 was achieved in 99.1% (95% CI: 95.0-100; n = 109/110) with one patient experiencing treatment failure, while n = 12/122 (9.8%) patients were excluded due to loss of follow-up (FU). 5 patients showed HCV reinfection after achieving SVR12. SS-patients achieved SVR in 96.6% (95% CI: 90.3-99.3%; n = 84/87) after exclusion of 10/99 (10.1%) patients who were lost to FU and 2 patients who died prior to SVR12 due to reasons not related to DAA therapy. Conclusions SOF/VEL given as DOT along with OAT in PWIDs at high risk of non-adherence to antiviral therapy including those with ongoing intravenous drug use resulted in excellent SVR rates similar to patients with presumed "excellent compliance" under standard drug intake.