title: Randomized trial of peginterferon α-2a plus ribavirin versus peginterferon α-2b plus ribavirin for chronic hepatitis C in Japanese patients.
abstract: BACKGROUND
  Pegylated interferon (PegIFN) plus ribavirin is the standard therapy for patients with chronic hepatitis C genotype 1. Although several randomized clinical trials have compared PegIFNα-2a with PegIFNα-2b, these 2 regimens have not been directly compared in Asian patients. We, therefore, compared the safety and antiviral efficacy of these agents in Japanese patients.
  
  
  METHODS
  A total of 201 PegIFN-naïve, chronic hepatitis C patients were randomly assigned to once-weekly PegIFNα-2a (180 μg) or PegIFNα-2b (60-150 μg) plus ribavirin. We compared the sustained virological response (SVR) rates between the 2 regimens and analyzed their effects in relation to baseline characteristics, including single nucleotide polymorphisms (SNPs) near the interleukin-28B (IL28B) gene (rs8099917).
  
  
  RESULTS
  PegIFNα-2a was associated with a higher SVR rate than PegIFNα-2b (65.3 vs. 51.0%, P = 0.039). PegIFNα-2a and SNPs near IL28B independently predicted SVR (odds ratio 2.36; 95% confidence interval [CI] 1.19-15.50, and odds ratio 7.31; 95% CI 3.45-4.68, respectively) in logistic regression analysis. PegIFNα-2a was more effective than PegIFNα-2b (81.8 vs. 62.7%, P = 0.014) in IL28B TT genotype patients, despite similarly low SVR rates in patients with TG or GG genotypes (36.4 vs. 35.9%). Patients weighing <60 kg, women, and patients aged >60 years had significantly higher SVR rates with PegIFNα-2a than with PegIFNα-2b (63.9, 61.3, and 67.3% vs. 43.8, 43.3,and 39.2%, respectively).
  
  
  CONCLUSIONS
  PegIFNα-2a plus ribavirin resulted in higher SVR rates than PegIFNα-2b plus ribavirin in Japanese patients. PegIFNα-2a-based treatment should therefore be the preferred choice for women, older or low-weight patients, and those with the IL28B TT genotype.
authors.affiliation: Department of Gastroenterology and Hepatology, NTT West Kyushu Hospital, 1-17-27 Shinyashiki, Kumamoto 862-8655, Japan. sho@ntthosp.jp
authors.forename: Shiho
authors.initials: S
authors.lastname: Miyase
authors.forename: Katsuki
authors.initials: K
authors.lastname: Haraoka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ouchida
authors.forename: Yuko
authors.initials: Y
authors.lastname: Morishita
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Fujiyama
mesh_terms: D000368:Aged; D000998:Antiviral Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005838:Genotype; D016174:Hepacivirus / Q000502:physiology*; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000235:genetics / Q000821:virology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000009:adverse effects / Q000627:therapeutic use*; D007372:Interferons; D007378:Interleukins / Q000235:genetics; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols / Q000009:adverse effects / Q000627:therapeutic use*; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use; D012254:Ribavirin / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D000095022:Interferon Lambda
chemical_list: D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D007372:Interferons; D007378:Interleukins; D011092:Polyethylene Glycols; D012367:RNA, Viral; D011994:Recombinant Proteins; D012254:Ribavirin; C000624353:interferon-lambda, human; D000095022:Interferon Lambda; C417083:peginterferon alfa-2b; C100416:peginterferon alfa-2a