1 San Francisco Department of Public Health, San Francisco, California, United States of America.
2 University of California San Francisco, San Francisco, California, United States of America.
3 University of California Berkeley School of Public Health, Berkeley, California, United States of America.
The advent of direct-acting antivirals for hepatitis C virus (HCV) and limited effectiveness of prevention have generated interest in "Treatment as Prevention" (TasP), in which those most likely to transmit HCV (i.e. people who inject drugs [PWID]) are treated to reduced secondary transmission. However, there are scant data regarding the feasibility of treating PWID at high risk for secondary transmission or the optimal approach to treatment delivery.
We conducted a 2:1 randomized trial of modified directly-observed (mDOT) versus unobserved HCV treatment with ledipasvir-sofosbuvir daily for 8 weeks among PWID with 36 weeks of follow-up in San Francisco from 2015-2017. We evaluated recruitment-enrollment, treatment completion, end-of-treatment and 12-week response, and reinfection rate.
Of 83 individuals eligible for screening, 72 (87.6%) attended the screening visit, 33 were eligible, and 31 enrolled; mean age was 42 years, 81% were male, 74% white. All but one participant (in the mDOT arm) completed treatment and 89.4% of mDOT and 96.6% of unobserved arm visits were attended. HCV was undetectable for 96.8% (30/31) at end of treatment and 89.7% (26/29) 12 weeks later (1 relapse, 1 reinfection), with no differences by arm. Two additional reinfections were subsequently identified, for a reinfection rate of 16.3 (95% CI 5.3-50.5) per 100 person-years of observation.
It was feasible to recruit active PWID for HCV treatment and achieve high retention, viral response, and satisfaction with either mDOT or unobserved protocols, supporting treatment of PWID at risk of transmitting HCV to others. The reinfection rate suggests we successfully reached a high-risk population and that successful HCV TasP initiatives may aim to be sufficient in scope to significantly lower prevalence in the community.