Administering direct-acting antiviral therapy for people who inject drugs at a syringe exchange site led to high sustained response rates in a pilot study in New York City, researchers reported at the recent Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle. Expanding treatment for this population could reduce hepatitis C virus (HCV) transmission and ultimately help eliminate hepatitis C as a public health threat.
The advent of direct-acting antiviral agents (DAAs) used in interferon-free regimens has revolutionised treatment for chronic hepatitis C. Most people can now be cured with well-tolerated oral therapy given for 8 to 12 weeks. But the new therapies are not yet reaching everyone who could benefit, especially marginalised populations such as people who inject drugs.
Benjamin Eckhardt of New York University and colleagues evaluated clinical outcomes from a prospective pilot programme offering hepatitis C treatment to active injection drug users at a needle and syringe service site.
"The introduction of direct acting antiviral agents for HCV has begun the discussion about potential viral elimination," the researchers noted as background. "To maximize the population impact of DAAs on the HCV epidemic, more people who inject drugs need to be cured of their infection."
A total of 45 people enrolled in the programme, of whom 34 applied for HCV medications and 26 started therapy and were included in the analysis. Of the treated participants, more than 90% were men, half were white, about 12% were black and more than 40% were Latino/Hispanic. The mean age was 46 years and they had been injecting for about 20 years on average. People with HIV co-infection were not included.
Nearly half were homeless and all received health coverage through Medicaid (for low-income people) or Medicare (for older people). About 60% were on opioid substitution therapy, but they reported ongoing injection drug use with a range of 4 to 150 injections during the past month.
More than half had HCV genotype 1, with about 20% each having genotypes 2 and 3. Most had not been previously treated for hepatitis C. A majority had absent, mild or moderate liver fibrosis, but three had advanced fibrosis (stage F3) and three had compensated cirrhosis (stage F4). People with decompensated liver disease were not treated on site and were instead referred to hepatology clinics.
Doctor visits, blood draws for lab tests and medication distribution all occurred at the syringe exchange site. About 40% used sofosbuvir/ledipasvir (Harvoni), 23% used sofosbuvir (Sovaldi) plus daclatasvir (Daklinza), 19% used sofosbuvir plus ribavirin alone and the rest used other regimens; altogether all but one received sofosbuvir-based therapy.
Among the 26 treated people, 22 (85%) achieved sustained virological response at 12 weeks post-treatment (SVR12). Of the rest, one discontinued treatment due to adverse events and one stopped early due to a lapse in insurance. Another person stopped treatment at 6 weeks due to incarceration but was still cured. Two people were found to have detectable HCV RNA within 4-6 weeks after completing treatment. But they both started with genotype 1a and ended with genotype 3, suggesting either reinfection or emergence of a second pre-existing strain that was unresponsive to the regimens used. Both were retreated and achieved SVR12.
"People who inject drugs can be effectively treated for hepatitis C with high rates of sustained virologic response," the researchers concluded. "Co-located treatment of hepatitis C within a harm reduction centre (needle exchange facility) is a potential approach to engage people who inject drugs in an accessible and de-stigmatised setting."
"The rates of re-infection in this population, and the impact of HCV treatment at a needle-syringe program on high risk behaviour and community-wide transmission (cure-as-prevention) need further investigation," they added.