Alain Litwin of Albert Einstein College of
Medicine presented findings from a study of people on OST treated with
sofosbuvir-based regimens.
This analysis looked at 61 participants
who started hepatitis C treatment in an on-site opiate substitution treatment
programme at three clinics in Manhattan, the Bronx and New Jersey. Just over
60% were men, 56% were Latino, 26% were black, 18% were white and the mean age
was about 54 years. HCV genotypes 1, 2 and 3 were all well represented.
Two-thirds were previously untreated and a quarter had cirrhosis.
Most participants (88%) were receiving
methadone, with a smaller number taking buprenorphine. Two-thirds had used any
illicit drugs within six months and 57% did so while on hepatitis C treatment.
Nearly three quarters had psychiatric conditions, most often depression or
anxiety. Almost all were on Medicaid, which provides health coverage for
low-income people.
Most participants were treated with
sofosbuvir plus ribavirin, though 12% also included pegylated interferon; 39%
were treated for 12 weeks and the rest for 24 weeks. Participants and providers
jointly decided whether to administer treatment one month at a time, one week
at a time, or using directly observed therapy at the clinic.
The overall
SVR12 rate was 80%. Sofosbuvir/ribavirin response rates were similar across
genotypes, with interferon improving response. Again, these SVR rates were
comparable to those seen in studies of non-injectors.
The researchers
looked at several of measures of adherence, all of which decreased over time.
Average daily adherence, for example, fell from 71% during weeks 1-12 of
treatment to 61% during weeks 13-24. Adherence decreased somewhat with illicit
drug use (though the change was not significant), but adherence and drug use
were not associated with SVR in a multivariate analysis. Adherence did not
differ based on monthly, daily or directly observed treatment administration.
“Rates of SVR are high in people who inject drugs initiating
sofosbuvir-based regimens within an on-site HCV treatment program,” the
researchers concluded. “Adherence (measured by electronic blister packs) is
suboptimal but in this small study adherence was not associated with SVR. Adherence significantly
decreased over [a] 24-week period, suggesting shorter courses of treatment
[are] important in people who inject drugs.”