Clinical trial : pharmacodynamics and pharmacokinetics of re-treatment with fixed-dose induction of peginterferon α-2a in hepatitis C virus genotype 1 true non-responder patients

Summary Background  Patients infected with hepatitis C virus genotype 1 who are true non-responders to previous therapy suffer from a very difficult-to-cure disease. New approaches to treatment are necessary. Aim  To explore the efficacy, pharmacokinetics and safety of fixed-dose induction with peginterferon α-2a and ribavirin in this difficult-to-cure population. Methods  Seventy-five hepatitis C virus genotype 1 true non-responder patients to a previous interferon-based combination regimen were randomised to receive peginterferon α-2a 360, 270 or 180 μg/week for 12 weeks, followed by 180 μg/week for 36 weeks, in combination with ribavirin (1000/1200 mg/day). Peginterferon α-2a concentration was measured throughout the study. Results  Sustained virological response rates were 38%, 30% and 18%, in the 360, 270 and 180 μg/week groups, respectively (relapse rates: 25%, 50% and 64%, respectively). The area under the serum concentration-time curve of peginterferon α-2a from 0–12 weeks increased in a dose-dependent manner (P < 0.0001) and was associated with the sustained virological response (odds ratio: 1.35; 95% CI: 0.89, 2.06). The three regimens were equally well tolerated. Conclusion  Fixed-dose induction of peginterferon α-2a resulted in increased drug exposure and improved the likelihood of achieving a cure, without compromising safety in hepatitis C virus genotype 1 true non-responder patients.