Efficacy of switching to entecavir monotherapy in Japanese lamivudine-pretreated patients.
OBJECTIVE
To assess the efficacy of switching Japanese chronic hepatitis B patients from lamivudine monotherapy to entecavir 0.5 mg/day.


METHODS
A retrospective analysis was conducted on 134 patients switched to entecavir between September 2006 and February 2008 for 6 months or more. Patients were divided into three groups based on viral load at entecavir switching point (baseline < 2.6, 2.6-5.0 and > 5.0 log(10) copies/mL).


RESULTS
At baseline, detection of lamivudine-resistant virus was highest in patients with higher hepatitis B virus (HBV) DNA (76% vs 23% in > or = 2.6 and < 2.6 log(10) copies/mL, respectively), and in patients with longest previous exposure to lamivudine (52%, 28% and 24% for > 3 years, 1-3 years and < 1 year, respectively). Two years after entecavir switching, HBV DNA suppression to less than 2.6 log(10) copies/mL was achieved in 100% (32/32), 92% (12/13) and 44% (4/9) of patients in the less than 2.6, 2.6-5.0 and more than 5.0 log(10) copies/mL baseline groups, respectively. Alanine aminotransferase (ALT) normalization occurred in 76-96% and 90-100% of patients following 1 and 2 years of entecavir treatment, respectively. One patient (2.6-5.0 log(10) copies/mL) with lamivudine-resistant mutants at baseline developed entecavir resistance at week 48 during follow up.


CONCLUSIONS
Switching to entecavir 0.5 mg/day achieves or maintains undetectable HBV DNA levels and ALT normalization over 2 years, especially in patients with viral load less than 5.0 log(10) copies/mL.
Suzuki
Fumitaka
F
Department of Hepatology, Toranomon Hospital, Tokyo, Japan. fumitakas@toranomon.gr.jp
Akuta
Norio
N
Suzuki
Yoshiyuki
Y
Yatsuji
Hiromi
H
Sezaki
Hitomi
H
Arase
Yasuji
Y
Hirakawa
Miharu
M
Kawamura
Yusuke
Y
Hosaka
Tetsuya
T
Kobayashi
Masahiro
M
Saitoh
Satoshi
S
Ikeda
Kenji
K
Kobayashi
Mariko
M
Watahiki
Sachiyo
S
Kumada
Hiromitsu
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000410:Alanine Transaminase / Q000097:blood; D000998:Antiviral Agents / Q000008:administration & dosage*; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D004279:DNA, Viral / Q000097:blood; D024882:Drug Resistance, Viral / Q000235:genetics; D005260:Female; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006515:Hepatitis B virus / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000188:drug therapy* / Q000208:ethnology; D006801:Humans; D007564:Japan; D019259:Lamivudine / Q000008:administration & dosage*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016017:Odds Ratio; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D019562:Viral Load; D055815:Young Adult
D000998:Antiviral Agents; D015415:Biomarkers; D004279:DNA, Viral; D019259:Lamivudine; C413685:entecavir; D006147:Guanine; D000410:Alanine Transaminase