Treatment of chronic hepatitis C in patients who failed interferon monotherapy: effects of higher doses of interferon and ribavirin combination therapy. The Virginia Cooperative Hepatitis Treatment Group

OBJECTIVE: The present study was designed to evaluate the effectiveness of interferon-ribavirin combination therapy for treatment of chronic hepatitis C virus (HCV) in patients who failed previous treatment with interferon monotherapy. METHODS: A total of 140 patients with well-documented chronic HCV who failed to achieve a virological (if HCV-RNA was assessed) or biochemical response (if HCV-RNA was not assessed) to interferon monotherapy, 3 mU three times weekly (TIW) for 3-18 months, were randomly assigned to one of three treatment groups. Group A patients were treated with 5 mU interferon TIW for 6 months. Ribavirin (1000-1200 mg daily) was added in those patients HCV-RNA positive at month 3. Group B patients were treated with 3 mU interferon TIW plus ribavirin (1000-1200 mg daily) for 6 months. The dose of interferon was increased to 5 mU TIW in those patients HCV-RNA positive at month 3. Group C patients were treated with 5 mU interferon TIW plus ribavirin (1000-1200 mg daily) for 6 months. Serum ALT and HCV-RNA were monitored during and after treatment for a total of 15 months. RESULTS: Seventeen percent of patients in group A became HCV-RNA negative by treatment month 3. Adding ribavirin resulted in one additional patient becoming HCV-RNA negative. However, none of the patients in this group achieved sustained virological response. Twenty-six percent of patients in group B became HCV-RNA negative by treatment month 3. Increasing the dose of interferon from 3 to 5 mU TIW increased virological response to 30%. However, sustained virological response was observed in only 14%. Thirty percent of patients in group C became HCV-RNA negative, but sustained virological response was observed in only 12%. Sustained virological response was found to be significantly greater in patients with a nontype I HCV genotype (p < 0.002) and in patients who had a decline in HCV-RNA titer to a value < 100,000 copies/ml during their previous course of interferon monotherapy (p < 0.0001). None of the 12 sustained responders were African Americans (p < 0.013). CONCLUSIONS: Retreatment of nonresponders with interferon-ribavirin combination therapy results in limited benefit; only 13% of patients achieved sustained virological response. Response was extremely poor in African Americans and those with HCV genotype 1.