Objectives: The efficacy of combination therapy with pegylated interferon (PEG IFN) alpha plus ribavirin (RBV) in the retreatment of chronic hepatitis C (CHC) in patients who previously failed combination standard IFN plus RBV or IFN monotherapy has not been well established.
Methods: Three hundred and twenty-one CHC patients including virologic nonresponders to combination IFN plus RBV (n = 219) or IFN monotherapy (n = 47), and relapsers to combination therapy (n = 55) were randomized to receive PEG IFN alpha-2b 1.5 microg/kg per wk plus RBV 800 mg per day (Regimen A, n = 160) or PEG IFN alpha-2b 1.0 microg/kg per wk plus RBV 1,000-1,200 mg per day (Regimen B, n = 161) for 48 wks.
Results: Sustained virologic response (SVR) occurred in 16% of the overall study population (Regimen A vs B, 18%vs 13%, p= 0.21), in 8% of the combination therapy nonresponders (10%vs 6%, p= 0.35), in 21% of the IFN monotherapy nonresponders (16%vs 27%, p= 0.35), and in 42% of the combination therapy relapsers (50%vs 32%, p= 0.18). In nonresponders to prior combination therapy, HCV ribonucleic acid levels <100,000 copies/mL at the end of the prior treatment course were associated with an increased SVR compared with levels >or=100,000 copies/mL (21%vs 5%, p= 0.002). In the overall study population, genotype 1 patients had lower SVR rates than others (14%vs 33%, p= 0.01), and African Americans had lower SVR than Caucasians (4%vs 18%, p= 0.01).
Conclusion: Combination therapy with PEG IFN alpha-2b plus RBV is more effective in patients who relapsed after combination standard IFN plus RBV than in nonresponders to either combination therapy or IFN monotherapy. There was no significant effect of dosing regimen.