Background: Patients with a history of intravenous drug abuse included in an official opioid substitution program represent an important subgroup of patients with chronic hepatitis C. The objective of this study was to assess the efficacy of and adherence to treatment with peginterferon and ribavirin in Austrian patients on stable opioid substitution therapy (OST).
Methods: This prospective, multicenter, observational, non-interventional trial (clinicaltrials.gov identifier, NCT01416610) included treatment-naïve patients with chronic hepatitis C on OST. Treatment consisted of peginterferon alpha-2a (PEGASYS®, 180 µg/week) plus ribavirin (COPEGUS®, 1000/1200 mg/day in genotypes (GT) 1/4 and 800 mg/day in GT 2/3) for 24-72 weeks, according to GT and viral response.
Results: The intention-to-treat (ITT) population comprised 88 patients. Mean duration of therapy was 6.0 ± 2.8 months. Treatment was discontinued earlier than planned in 34 out of 88 patients (39%), mainly because of poor adherence or side effects of treatment. At the end of treatment 65/88 patients (74%) were PCR negative. During follow-up, 5 patients relapsed. Only 44/88 patients (50%) could be evaluated 24 weeks after the end of treatment. Sustained virologic response 24 weeks after end of therapy (SVR24) was documented in 39/88 patients (44%). If only patients were considered who finished treatment as planned and for whom results at follow-up week 24 were available, the SVR24 rate was 89% (32/36).
Conclusion: Despite favorable prognostic factors, such as young age and a high proportion of GT3, SVR rates were low in this cohort of patients receiving OST, the main reason being poor adherence; however, in those patients completing treatment, the SVR rate was high.
Keywords: Chronic hepatitis C; Peginterferon; People who inject drugs (PWID); Ribavirin.