title: Antiviral efficacy of entecavir versus entecavir plus adefovir for hepatitis B virus rtA181V/T mutants alone.
abstract: OBJECTIVE
  Hepatitis B virus (HBV) rtA181V/T mutants developed by long-term nucleos(t) ide analogue therapy are known to present cross-resistance for other nucleos (t) ide analogues, except entecavir (ETV). Some studies reported that HBV rtA181V/T mutants could induce cross-resistance to ETV and showed incomplete response as well as persistence of HBV DNA, despite rescue therapy by ETV. This study aimed to investigate the antiviral efficacy of ETV monotherapy and ETV plus adefovir (ADV) as rescue therapy for HBV rtA181V/T single mutation.
  
  
  METHODS
  A total of 30 patients who received ETV alone (1.0 mg/day, n = 16) or ETV plus ADV (10.0 mg/day, n = 14) over 48 weeks between April 2008 and October 2011 were enrolled. Virological, biochemical, and serological response at 48 weeks of rescue therapy were investigated retrospectively.
  
  
  RESULTS
  No significant difference in baseline characteristics was observed between the ETV group and the ETV plus ADV group. Virological response showed complete response (62.5 vs. 42.9%), partial response (6.3 vs. 28.6%), non-response (25.0 vs. 28.6%), and virological breakthrough (6.3 vs. 0%) in the two groups, respectively. Virological response did not statistically differ between both groups (P = 0.278). No significant difference in the mean reduction of serum HBV DNA and biochemical response was observed between both groups (4.3 ± 2.9 vs. 4.1 ± 1.8 log 10 IU/ml; P = 0.294 and 88.9 vs. 100%; P = 1.000, respectively). In addition, no significant difference in HBeAg loss or seroconversion was observed between the two groups (26.7 vs. 28.6%; P = 1.000).
  
  
  CONCLUSIONS
  ETV monotherapy and ETV plus ADV therapy were clinically effective and comparable as rescue therapy for HBV rtA181V/T mutants alone.
authors.forename: Myung Jin
authors.initials: MJ
authors.lastname: Oh
authors.affiliation: Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, South Korea.
authors.forename: Heon Ju
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage*; D004279:DNA, Viral / Q000235:genetics; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006515:Hepatitis B virus / Q000235:genetics*; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D063065:Organophosphonates / Q000008:administration & dosage*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D063065:Organophosphonates; C413685:entecavir; D006147:Guanine; C053001:adefovir; D000225:Adenine
references.citation: J Med Virol. 2007 Mar;79(3):212-9
references.pmid: 17245716
references.citation: Hepatology. 2000 Oct;32(4 Pt 1):803-6
references.pmid: 11003626
references.citation: J Hepatol. 2008 Apr;48(4):540-7
references.pmid: 18279995
references.citation: Gastroenterology. 2009 Nov;137(5):1593-608.e1-2
references.pmid: 19737565
references.citation: World J Gastroenterol. 2012 Dec 28;18(48):7149-57
references.pmid: 23326119
references.citation: Clin Mol Hepatol. 2013 Mar;19(1):29-35
references.pmid: 23593607
references.citation: Hepatology. 2008 Jul;48(1):88-98
references.pmid: 18537180
references.citation: J Hepatol. 2007 Oct;47(4):492-8
references.pmid: 17692425
references.citation: J Hepatol. 2010 Sep;53(3):449-54
references.pmid: 20646776
references.citation: Hepatology. 2009 Sep;50(3):661-2
references.pmid: 19714720
references.citation: J Hepatol. 2005 Dec;43(6):937-43
references.pmid: 16168522
references.citation: Clin Mol Hepatol. 2012 Jun;18(2):109-62
references.pmid: 22893865
references.citation: N Engl J Med. 2008 Oct 2;359(14):1486-500
references.pmid: 18832247
references.citation: J Hepatol. 2012 Jul;57(1):167-85
references.pmid: 22436845
references.citation: Hepatology. 2006 Sep;44(3):703-12
references.pmid: 16941700
references.citation: Antivir Ther. 2007;12(3):355-62
references.pmid: 17591025
references.citation: Antiviral Res. 2010 Mar;85(3):512-9
references.pmid: 20034521
references.citation: Gastroenterology. 2011 Jan;140(1):132-43
references.pmid: 20955704
references.citation: JAMA. 2006 Jan 4;295(1):65-73
references.pmid: 16391218
references.citation: Expert Rev Anti Infect Ther. 2009 Apr;7(3):309-20
references.pmid: 19344244
references.citation: J Hepatol. 2006 Feb;44(2):283-90
references.pmid: 16338024
references.citation: Gastroenterology. 2006 Mar;130(3):678-86
references.pmid: 16530509
references.citation: Hepatol Int. 2008 Jun;2(2):147-51
references.pmid: 19669299
references.citation: J Hepatol. 2008 May;48(5):747-55
references.pmid: 18331765
references.citation: N Engl J Med. 2008 Dec 4;359(23):2442-55
references.pmid: 19052126