A study of people with hepatitis C virus (HCV) infection receiving opioid agonist therapy found high rates of HCV treatment completion regardless of treatment model, although directly observed therapy yielded the greatest adherence rate.
From October 2013 to April 2017, researchers conducted the partly industry-funded Prevent Resistance Eliminate Virus and Improve Life (PREVAIL) study at three opioid agonist therapy programs in Bronx, New York. They recruited adults with genotype 1 HCV infection who were willing to receive antiviral therapy on site in the opioid agonist therapy program. A total of 158 people were randomly assigned to a study group, and 150 (mean age, 51 years) initiated treatment with one of two intensive interventions, directly observed therapy (n=51) and group treatment (n=48), or with a control, self-administered individual treatment (n=51). The primary outcome was adherence, measured by using electronic blister packs, and secondary outcomes included HCV treatment completion and sustained virologic response 12 weeks after treatment completion. Results were published online on April 9 by Annals of Internal Medicine.
About 65% of participants had positive results on urine drug testing during the six months before treatment, and 75% reported ever injecting drugs. Overall adherence, estimated from mixed-effects models using the daily timeframe, was 78% (95% CI, 75% to 81%) and was greater among participants randomly assigned to directly observed therapy than those assigned to self-administered individual treatment (86% vs. 75%; difference, 11% [95% CI, 5% to 18%]; Bonferroni-corrected P=0.001). There were no significant differences in adherence between participants randomly assigned to group treatment versus those assigned to self-administered individual treatment (80% vs. 75%; difference, 5% [95% CI, −2% to 11%]; Bonferroni-corrected P=0.29).
The HCV treatment completion rate was 97% among all participants, including those actively using drugs, with no significant differences between groups (P=0.53). The overall sustained virologic response was 94% (95% CI, 89% to 97%): 98% in the directly observed therapy group, 94% in the group treatment group, and 90% in the self-administered individual treatment group (P=0.152).
The authors noted limitations, such as the fact that all participants did not receive the same therapy because the study occurred during the emergence of combination direct-acting antiviral regimens. In addition, the findings may not be generalizable to rural settings or to persons who inject drugs who are not enrolled in opioid agonist therapy programs, they said.
The findings support treating people with HCV infection who are receiving opioid agonist therapy, regardless of current drug use, the authors said. “Our data demonstrate that active drug use has no substantial effect on virologic outcomes in HCV treatment,” they wrote.