Retreatment of hepatitis C with consensus interferon and ribavirin after nonresponse or relapse to pegylated interferon and ribavirin: a national VA clinical practice study.

Background: Studies of the retreatment with consensus interferon (CIFN) and ribavirin (RBV) of hepatitis C virus (HCV)-infected patients who failed prior pegylated interferon alfa/ribavirin (PEG-IFN/RBV) have found quite variable efficacy and tolerability of this therapy. As such, CIFN/RBV use and efficacy in clinical practice were evaluated within the Department of Veterans Affairs (VA), the largest national, integrated system for HCV care.

Aims: The purpose of this study was to determine rates of sustained virologic response (SVR) and patterns of CIFN/RBV use in the VA. Methods included retrospective review of national VA data in HCV-infected patients who had previously failed≥12 weeks of PEG-IFN/RBV and were prescribed CIFN/RBV between October 1, 2003 and September 30, 2006.

Results: A total of 597 patients met the study criteria. CIFN was primarily dosed as 15 mcg subcutaneously daily combined with standard doses of RBV. Mean treatment duration was 21 weeks; CIFN was discontinued within 4 weeks in 24%. Hematological growth factors were used in 49%. Post-treatment viral loads were available in 385 patients. SVR to CIFN/RBV was achieved in 11%, and was significantly higher in prior PEG-IFN/RBV relapsers compared with nonresponders (31% vs. 6%, respectively; P<0.0001). A 2-log10 or greater drop in HCV RNA after 24 weeks of PEG-IFN/RBV was a predictor of subsequent SVR to CIFN/RBV.

Conclusions: CIFN/RBV was used frequently in clinical practice for retreatment of PEG-IFN/RBV. In this setting, early treatment discontinuation was common. Overall SVR was low, although response was significantly better in prior PEG-IFN/RBV relapsers and those who had a 2-log(10) or greater decline than in nonresponders.