More than half of injection drug users worldwide test positive for hepatitis C virus (HCV), yet they remain largely untreated, researchers contend. Many countries, including the United States, still have restrictions on reimbursement of direct-acting antiviral (DAA) therapy for people with recent injection drug use, which effectively prevents them from receiving treatment.
Making matters worse, many practitioners hesitate to prescribe therapy for injection drug users due to concerns about poor adherence, response to therapy, and risk of reinfection.
Now, a study in The Lancet Gastroenterology & Hepatology reports that people with recent injection drug use and people on opioid substitution therapy respond well to DAA therapy, regardless of drug use before or during treatment. These patients should be given priority for therapy, not restrictions, as a means of potentially reducing HCV transmission, investigators concluded.
“Given that people who inject drugs represent 23% of all new infections globally, HCV treatment should be increased among these people as part of efforts to eliminate HCV,” wrote investigators led by infectious disease specialist Greg Dore, MBBS, MPH, PhD, head of the Viral Hepatitis Clinical Research Program, Kirby Institute, University of New South Wales, Sydney, Australia.
“These data provide important evidence to support HCV treatment among people with recent injection drug use and have the potential to change clinical practice and health policy globally,” Dr. Dore and colleagues noted.
High response rate
The researchers enrolled 103 adults from 19 centers worldwide in order to obtain data on HCV treatment outcomes that could guide clinical management and support treatment access for injection drug users. Patients were HCV positive, DAA treatment naïve, and reported opioid injection drug use within 6 months of enrollment.
Fifty-nine percent of subjects were on opioid substitution therapy, 74% had injected in the prior month, and 26% had injected at least daily in the prior month. The most commonly injected drugs were heroin (55%), methamphetamines (30%), and other opioids (21%).
Patients were given a 12-week course of a once-daily oral combination pill of sofosbuvir (400 mg) and velpatasvir (100 mg). To track adherence, medication was distributed weekly in an electronic blister pack integrated with a sensor that recorded the time and date that each daily dose was punched out.
Of the 103 participants, 100 (97%) completed the 12 weeks of treatment and 97 (94%) achieved sustained virologic response (SVR), with no virologic failures.
Treatment was generally well tolerated, although it had no effect on injection drug use. Data downloads from the electronic blister packs showed that median adherence to therapy was 94%.
Drug use before and during treatment didn’t affect SVR, researchers noted, as the number of patients who achieved SVR was the same for those who had recent injection drug use as for those who didn’t.
“These data provide evidence to inform international guidelines on the management of HCV infection in people with recent injection drug use and support the removal of restrictions for the reimbursement of DAA therapy among people with HCV infection and recent injection drug use that are in place in several countries,” Dr. Dore and colleagues wrote.
In an accompanying editorial, infectious disease specialists from the Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, called for an end to the restrictions on insurance reimbursement for treating HCV-positive injection drug users.
“This study provides the scientific burden of proof that persistence of these restrictions is unwarranted and unsupported by data,” they wrote. “We now need to focus on ways to capitalize on the provision of HCV treatment for people who inject drugs and optimize engagement with this patient population to not only cure HCV but also reduce harms associated with substance use while they are engaged in health care.”
This study (including study drugs) was funded by a research grant from Gilead Sciences and was sponsored by the Kirby Institute.