Comparative trials of peginterferon α2a and peginterferon α2b for chronic hepatitis C

Abstract

Standard of care for patients with chronic hepatitis C is pegylated interferon (pegIFN) combined with ribavirin (Rbv). It results in persistent viral eradication and prevents the progression of liver disease and the associated complications in about 50% of treated patients. Currently, two PegIFNs are available that differ significantly in terms of pharmacokinetic and pharmacodynamic profiles as a consequence of different pegylation chemistries. While the registration trials of the two therapeutic regimens demonstrated the superiority of each PegIFN vs the native IFN α2b, the superiority of one regimen over the other in terms of treatment efficacy remains unknown. Retrospective cohort studies and randomized prospective head-to-head trials have attempted to resolve the considerable controversy over this issue and support evidence-based treatment decisions.

HCV genotype 1a shows a better virological response to antiviral therapy than HCV genotype 1b

“…At present the superiority of one regimen over the other in terms of treatment efficacy remains unknown. The performance of the two drugs has not been explored in patients stratified by treatment modifiers such as fibrosis stage, basal viral load, insulin resistance, age and it is unlikely that future effort will extend current knowledge as we enter in the era of protease and polymerase inhibitors [21]. …”

Efficacy and Tolerability of Peginterferonα-2a and Peginterferonα-2b, Both plus Ribavirin, for Chronic Hepatitis C: A Meta-Analysis of Randomized Controlled Trials

“…Maintaining a high ribavirin dose (≥12 mg/kg/day) during the full treatment period can lead to suppression of relapse in HCV-1 patients responding to peginterferon α -2b plus ribavirin. Ribavirin dosing seems to be instrumental in preventing posttreatment relapse [35], and ribavirin concentration in the later stages of treatment is an important marker for discriminating relapse [34, 36]. In the present meta-analysis, no significant difference in peginterferon and/or ribavirin dose reduction was found between the two groups.…”

“…Many factors might have contributed to the difference in the findings above. Some of these factors include differences in epidemiological and genetic characteristics, mean body weight, distribution of genotype CC in the IL28B polymorphism, and ribavirin dose reduction schemes applied to the two regimens [34]. Maintaining a high ribavirin dose (≥12 mg/kg/day) during the full treatment period can lead to suppression of relapse in HCV-1 patients responding to peginterferon α -2b plus ribavirin.…”

“…For the peginterferon α -2a arm, the dose was reduced to 600 mg/day. The abrupt reduction of ribavirin dose to 600 mg/day might have played a crucial role in the high relapse rates observed in patients receiving the peginterferon α -2a regimen [8–10, 34]. …”

Interleukin‐28b CC genotype predicts early treatment response and CT/TT genotypes predicts non‐response in patients infected with HCV genotype 3

“…Nearly 20% of patients infected chronically with HCV develop cirrhosis of the liver and have a high chance of developing hepatocellular carcinoma (HCC) [Rodger et al, ]. A combination of pegylated interferon‐α (PegIFN) and ribavirin (RBV) therapy is considered as the standard of care for HCV treatment with response rates ranging from 48% to 88% [Abdelmalek et al, ; Shiffman et al, ; Rumi et al, ]. PegIFN has both direct antiviral and immunomodulatory effects and ribavirin promotes a type 1 cytokine‐mediated immune response which can further enhance antiviral immune responses [Tam et al, ; Yee, ; Folgori et al, ; Pasha et al, ].…”