Equal efficacy between the two types of peginterferon on HCV: a matter of relapse?

Two types of peginterferon alfa (2a and 2b) are available for the treatment of chronic hepatitis C genotype 1 or non-1. Comparative studies of bitherapy suggest equivalent results in terms of sustained virologic response for the two types of interferon possibly with a slight advantage in favor of type 2a. However, these studies report only limited data concerning relapse. We analyzed studies comparing the two types of peginterferon with data concerning relapse. In the 6 studies examined (8538 patients), peginterferon 2a was clearly associated with a much higher rate of end of treatment response but also a higher relapse rate than type 2b (29.3% vs 21.1%; relative risk of relapse with peginterferon 2a:1.54 [1.35-1.76], p=0.0024). These data are highlighted in overweight patients. We tried to explain these differences between these two types of interferon by discussing in terms of pharmacokinetics. Peginterferon remains the cornerstone of HCV treatment and must be carefully chosen on the basis of the patient's history and cofactors. These data are important and must be considered in the era of DAA.