title: A comparison of clevudine and entecavir for treatment-naïve patients with chronic hepatitis B: results after 2 years of treatment.
abstract: BACKGROUND
  This study was undertaken to compare the efficacy, safety, and resistance profile of clevudine (CLV) and entecavir (ETV) following a 2-year treatment period.
  
  
  METHODS
  One hundred and eight Korean patients from the prior 48-week study were followed with continuous therapy for up to 2 years and monitored for hepatitis B virus (HBV) DNA levels, HBeAg seroconversion, serum ALT, emergence of drug-resistant mutant HBV, and drug-related adverse events.
  
  
  RESULTS
  A complete virological response during the 2-year treatment period occurred in 68.0 % in the CLV group and in 84.5 % in the ETV group (p = 0.043). The cumulative percentage of patients with sustained virological responses at 2 years was 54.0 and 77.6 % in the CLV and ETV group, respectively (p = 0.010). Virological breakthrough occurred in 12 patients in the CLV group; however, there were none in the ETV group (p < 0.001). HBeAg seroconversion rates were not different between the two groups. In patients who maintained sustained virological responses at 2 years, the mean reduction in HBsAg titer was -0.24 and -0.06 log IU/ml in the CLV and ETV group, respectively (p > 0.05). Clinical myopathy occurred in seven patients in the CLV group; however, this was not observed in the ETV group (p = 0.004).
  
  
  CONCLUSIONS
  ETV was associated with a significantly higher virological response rate than CLV at 2 years. ETV was superior to CLV in terms of the drug resistance profile and the development of clinical myopathy. Further studies to see whether the unique characteristic of CLV to reduce HBsAg titer is associated with the removal of ccc-DNA from hepatocytes and the remission of the disease are needed.
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Geum-Youn
authors.initials: GY
authors.lastname: Gwak
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Sung June
authors.initials: SJ
authors.lastname: Eo
authors.affiliation: Department of Medicine, Kangnam Sacred Heart Hospital, Hallym University, Seoul, South Korea.
authors.forename: Su Rin
authors.initials: SR
authors.lastname: Shin
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Moon Seok
authors.initials: MS
authors.lastname: Choi
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Joon Hyoek
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Kwang Cheol
authors.initials: KC
authors.lastname: Koh
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Seung Woon
authors.initials: SW
authors.lastname: Paik
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. bc11.yoo@samsung.com.|Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul, 135-710, South Korea. bc11.yoo@samsung.com.
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Yoo
keywords: 2 years; Chronic hepatitis B; Clevudine; Entecavir