title: The virological response in Koreans infected with HCV genotype 1 did not differ between groups treated with a full dose or reduced dose (≥80 % full dose) of peginterferon alfa-2a: a prospective randomized multicenter trial.
abstract: OBJECTIVE
  A high rate of sustained viral response (SVR) in Koreans with chronic hepatitis C (CHC) is related to a favorable IL28B genotype. We compared two dosing strategies for peginterferon alfa-2a in Koreans with CHC and defined the combined effect of polymorphisms and dosing on the virological response.
  
  
  METHODS
  A total of 178 treatment-naïve patients with CHC genotype 1 were prospectively enrolled. All patients were randomly assigned to treatment with one of two peginterferon alfa-2a regimens: 180 μg per week for 48 weeks (full-dose group) or 180 μg per week during the first 12 weeks followed by 135 μg per week for the next 36 weeks (dose-reduction group). Polymorphisms related to IL28B, ITPA, C20orf194 and SLC29A1 were studied.
  
  
  RESULTS
  SVR rates did not differ between the full-dose and dose-reduction groups (56.5 and 51.2 %, respectively, p = 0.474). The frequency of additional reductions of the peginterferon dose because of adverse events was higher in the full-dose group than in the dose-reduction group. SVR rates in patients homozygous for the IL28B major allele were higher than those in patients for the other IL28B alleles. For patients with unfavorable IL28B genotypes, SVR was less likely to be achieved in the dose-reduction group than in the full-dose group.
  
  
  CONCLUSIONS
  In Koreans with HCV genotype 1, the virological response to treatment did not differ between a full dose and reduced dose (≥80 % of full dose) of peginterferon alfa-2a. However, in the patients with unfavorable IL28B genotypes, the full-dose treatment of peginterferon alfa-2a may be beneficial.
authors.affiliation: Department of Internal Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea, Incheon, Korea. doctorkwon@catholic.ac.kr.
authors.forename: Jung Hyun
authors.initials: JH
authors.lastname: Kwon
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-040, Korea. baesh@catholic.ac.kr.
authors.forename: Si Hyun
authors.initials: SH
authors.lastname: Bae
authors.affiliation: Department of Internal Medicine, Pusan Paik Hospital, Inje University of Korea, Gaegum-dong 633-165, Busanjin-gu, Pusan, 614-735, Korea. yiyh0105@inje.ac.kr.
authors.forename: Youn Jae
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Inha University School of Medicine, Incheon, Korea. jin@inha.ac.kr.
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Bucheon Soonchunhyang Hospital, Soonchunhyang University of Korea, Bucheon, Korea. liverkys@schmc.ac.kr.
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Dongsan Hospital, Keimyung University of Korea, Taegu, Korea. gastro@dsmc.or.kr.
authors.forename: Jae Seok
authors.initials: JS
authors.lastname: Hwang
authors.affiliation: Department of Internal Medicine, Kyungpook National University Hospital, Kyungpook National University of Korea, Taegu, Korea. wytak@knu.ac.kr.
authors.forename: Won Young
authors.initials: WY
authors.lastname: Tak
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul, 137-040, Korea. garden@catholic.ac.kr.
authors.forename: Jeong Won
authors.initials: JW
authors.lastname: Jang
authors.affiliation: Department of Internal Medicine, Chungnam National University Hospital, Chungnam National University of Korea, Taejon, Korea. gie001@cnuh.co.kr.
authors.forename: Byung Seok
authors.initials: BS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Ilsan Paik Hospital, Inje University of Korea, Ilsan, Korea. jsleemd@paik.ac.kr.
authors.forename: June Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, National Health Insurance Corporation Ilsan Hospital, Ilsan, Korea. cklee33@nhimc.or.kr.
authors.forename: Chun Kyon
authors.initials: CK
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Wonju Christian Hospital, Yonsei University of Korea, Wonju, Korea. baiksk@yonsei.ac.kr.
authors.forename: Soon Koo
authors.initials: SK
authors.lastname: Baik
authors.affiliation: Department of Internal Medicine, Ulsan University Hospital, Ulsan University of Korea, Ulsan, Korea. nhpark@uuh.ulsan.kr.
authors.forename: Neung Hwa
authors.initials: NH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Konyang University Hospital, Konyang University of Korea, Taejon, Korea. green740@naver.com.
authors.forename: Tae Hee
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Chuncheon Sacred Heart Hospital, Hallym University of Korea, Chuncheon, Korea. djkim@hallym.ac.kr.
authors.forename: Dong Joon
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Department of Pharmacology and PharmacoGenomics Research Center, Inje University of Korea, Pusan, Korea. karis@hanmail.net.
authors.forename: Jae-Seok
authors.initials: JS
authors.lastname: Choi
authors.affiliation: Department of Pharmacology and PharmacoGenomics Research Center, Inje University of Korea, Pusan, Korea. phshinjg@gmail.com.|Department of Clinical Pharmacology, Busan Paik Hospital, Inje University of Korea, Pusan, Korea. phshinjg@gmail.com.
authors.forename: Jae-Gook
authors.initials: JG
authors.lastname: Shin
authors.affiliation: Clinical Research Coordinating Center for Catholic Medical Center, The Catholic University of Korea, Seoul, Korea. y1693@catholic.ac.kr.
authors.forename: Hyeon Woo
authors.initials: HW
authors.lastname: Yim
keywords: Chronic hepatitis C; Genotype 1; IL28B; Interferon dosing; Polymorphism