CHU de Bordeaux, France.
IFN-gamma 1b improves alpha IFN inhibition of HCV replication in replicon system. We described virological response after addition of IFN-gamma to a combination of ribavirin/PEG-IFN α-2a or α-2b.
In this non comparative, multicenter trial, patients chronically infected by HCV who were non responders to a previous treatment by PEG-IFN and Ribavirin (RIBA) were re-started on a regimen of PEG-IFN α-2a (180μg/week) + ribavirin (1000-1200mg/day) for 16 weeks. If HCV RNA decreased less than 2 log(10) copies/ml (non-responders) and if Peg-IFN α-2a and RIBA dosages were unchanged while tolerance was good, IFN-gamma 1b (100 μg 3 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-gamma 1b).
Among 48 patients started on dual therapy, 23 patients (47%) were non-responders at week 12, and received IFN-gamma 1b from week 16 onwards. Their mean HCV RNA (log(10) 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 log(10) IU/ml. One case of grade 4 neutropenia was reported.
Among strictly selected non-responders, IFN-gamma 1b (at a dosage of 100μg thrice a week) in combination to PEG-IFN α-2a and ribavirin failed to show virological efficacy.