Impact of ribavirin priming on viral kinetics and treatment response in chronic hepatitis C genotype 1 infection.

Ribavirin amplifies the interferon-alpha (IFN) signalling cascade. As ribavirin needs 4 weeks to reach steady state, ribavirin priming may optimize hepatic IFN sensitivity before starting a pegylated (PEG)-IFN/ribavirin combination therapy. This study investigated potential benefits of ribavirin priming prior to PEG-IFN2a/ribavirin combination therapy on viral kinetics, on-treatment and sustained virological response (SVR) in chronic hepatitis C virus (HCV) genotype 1 infection. Sixty-eight treatment naive patients were randomized 2:2:1 to ribavirin (ribavirin arm) or placebo (placebo arm) or PEG-IFN2a (PEG-IFN2a arm) for 6 weeks prior to 12 weeks of PEG-IFN2a/ribavirin combination therapy within a double-blind, placebo-controlled trial. Then, standard PEG-IFN2a/ribavirin combination therapy according to the German guidelines was continued under the responsibility of the investigators. Ribavirin was given according to body weight and PEG-IFN2a at a dose of 180 μg subcutaneously once/week. During ribavirin priming, HCV RNA showed a decline of -0.58 log10  IU/mL (P < 0.001) that was unrelated to the IL28B rs12979860 genotype (CC vs CT/TT, P = 0.244). Ribavirin priming did neither increase the PEG-IFN2a-induced first- or second-phase viral decline (P values >0.100) nor on-treatment response or SVR (HCV RNA undetectable at week 12 of combination therapy: ribavirin arm 56%, placebo arm 38%, PEG-IFN2a arm 50%; SVR: ribavirin arm 41%, placebo arm 54%, PEG-IFN2a arm 50%; P values >0.300). In conclusion, ribavirin monotherapy showed a significant antiviral activity that was not influenced by the IL28B genotype. Ribavirin priming prior to PEG-IFN2a/ribavirin combination therapy did neither increase the first- or second-phase viral decline nor on-treatment response or SVR.