Efficacy of 24 weeks treatment with peginterferon alfa-2b plus ribavirin in patients with chronic hepatitis C infected with genotype 1 and low pretreatment viremia.

Previous studies using standard interferon and ribavirin combination therapy suggested that patients infected with HCV-1 and a low pretreatment HCV-RNA level can be treated for 24 weeks without compromising sustained virologic response rates. The aim of the present study was to investigate this schedule in the era of pegylated interferon-alpha plus ribavirin. Patients chronically infected with HCV-1 (n=235) and a screening viremia < or =600,000 IU/mL (real-time PCR) were treated with peginterferon alfa-2b 1.5 microg/kg subcutaneously once weekly plus ribavirin 800-1400 mg/day based on body weight for 24 weeks. End-of-treatment and sustained virologic response rates were 80 and 50%, respectively. The 48-week historical control (Manns et al., Lancet 2001;358:958-65) had similar end-of-treatment (74%) but higher sustained virologic response rates (71%). This difference was due to a high virologic relapse rate after 24 weeks of therapy (37%) compared with the historical control (4%). A subset of patients who had undetectable serum HCV-RNA at treatment week 4, however, achieved similar sustained virologic response rate (89%) as in the control group (85%). HCV-1 infected patients with a low baseline HCV-RNA concentration who become HCV-RNA negative at week 4 may be treated for 24 weeks without compromising sustained virologic response rates.