Peginterferon alpha-2a combination therapies in chronic hepatitis C patients who relapsed after or had a viral breakthrough on therapy with standard interferon alpha-2b plus ribavirin: a pilot study of efficacy and safety.

There are no established therapeutic regimens for hepatitis C virus (HCV) patients who relapse following treatment with interferon alpha-2b and ribavirin or those who break through while on interferon alpha-2b and ribavirin. We therefore evaluated various combination therapies in HCV patients who relapsed or experienced a viral breakthrough. Patients (n = 124) were randomized to 48 weeks of treatment with once-weekly subcutaneous injections of 180 microg pegylated (peg-) interferon alpha-2a plus oral ribavirin (800-1000 mg/day), mycophenolate mofetil (2 g/day), amantadine (200 mg/day), or ribavirin and amantadine and followed for an additional 24 weeks. The sustained virologic response was higher in patients administered peginterferon alpha-2a plus ribavirin (38%) or ribavirin and amantadine (45%) than in those administered peginterferon alpha-2a plus mycophenolate mofetil (17%) or amantadine (10%). As in previous studies, patients with genotype non-1 and those with lower viral loads had better responses than those with genotype 1 and high viral loads, though the differences did not reach significance. The four treatment regimens had similar safety profiles, except that patients receiving ribavirin had greater maximal hemoglobin decreases. These findings suggest that the combination of peginterferon alpha-2a plus ribavirin or with ribavirin and amantadine is effective in some HCV patients who relapse after treatment with interferon alpha-2b plus ribavirin.