Interferon-gamma with peginterferon alpha-2a and ribavirin in nonresponder patients with chronic hepatitis C (ANRS HC16 GAMMATRI).

Background and Aim Interferon-gamma-1b (IFN-γ-1b) improves alpha interferon (IFN-α) inhibition of hepatitis C virus (HCV) replication in replicon system. We described virological response after addition of IFN-γ to a combination of ribavirin/peginterferon (PEG-IFN)-α-2a or α-2b. Methods In this non-comparative, multicenter trial, patients chronically infected by HCV who were nonresponders to a previous treatment by PEG-IFN and ribavirin were restarted on a regimen of PEG-IFN-α-2a (180 μg/week) + ribavirin (1000–1200 mg/day) for 16 weeks. If HCV-RNA decreased less than 2 log10 copies/mL (nonresponders), and if PEG-IFN-α-2a and ribavirin dosages were unchanged while tolerance was good, IFNγ-1b (100 μg three times per week) was added for the last 32 weeks of treatment. Virological response was evaluated at week 28 (12 weeks after initiation of IFN-γ-1b). Results Among the 48 patients started on dual therapy, 23 patients (47%) were nonresponders at week 12 and received IFN-γ-1b from week 16 onward. Their mean HCV-RNA (log10 IU/mL) was 6.83 at baseline, 5.81 at week 12, and 5.63 at week 28. No patient reached undetectable HCV-RNA at week 28 (upper bound of 95% confidence interval: 14.8%); none had a decrease > 1 log10 IU/mL. One case of grade 4 neutropenia was reported. Conclusion Among the strictly selected nonresponders, IFN-γ-1b (at a dosage of 100 μg thrice a week) in combination with PEG-IFN-α-2a and ribavirin failed to show virological efficacy.