Peginterferon α-2b and ribavirin therapy in chronic hepatitis C genotype 4:: impact of treatment duration and viral kinetics on sustained virological response

Background: The response rates and duration of peginterferon alpha ( PEG- IFN- a) and ribavirin combination therapy in chronic hepatitis C genotype 4, the prevalent genotype in the Middle East and Africa, are poorly documented. Aims: To compare the efficacy and safety of 24, 36, or 48 weeks of PEG- IFN- alpha- 2b and ribavirin therapy in chronic hepatitis C genotype 4. Methods: In this prospective, randomised, double blind study, 287 patients with chronic hepatitis C genotype 4 were randomly assigned to PEG- IFN-alpha- 2b ( 1.5 mg/ kg) once weekly plus daily ribavirin ( 1000 - 1200 mg) for 24 weeks ( group A, n = 95), 36 weeks ( group B, n = 96), or 48 weeks ( group C, n = 96) and followed for 48 weeks after completion of treatment. Early viral kinetics and histopathological evaluation of pre- and post treatment liver biopsies were performed. The primary end point was viral clearance 48 weeks after completion of treatment. Results: Sustained virological response was achieved in 29%, 66%, and 69% of patients treated with PEGIFN-alpha- 2b and ribavirin for 24, 36, and 48 weeks, respectively, by intention to treat analysis. No statistically significant difference in sustained virological response rates was detected between 36 and 48 weeks of therapy ( p = 0.3). Subjects with sustained virological response showed greater antiviral efficacy ( e) and rapid viral load decline from baseline to treatment week 4 compared with non- responders and improvement in liver histology. The incidence of adverse events was higher in the group treated for 48 weeks. Conclusion: PEG- IFN- a- 2b and ribavirin for 36 or 48 weeks was more effective in the treatment of chronic hepatitis C genotype 4 than treatment for 24 weeks. Thirty six week therapy was well tolerated and produced sustained virological and histological response rates similar to the 48 week regimen.