title: Efficacy of entecavir switch therapy in chronic hepatitis B patients with incomplete virological response to telbivudine.
abstract: BACKGROUND
  The roadmap concept suggests the use of on-treatment HBV DNA to guide treatment strategy of chronic hepatitis B patients treated by telbivudine. Our aim was to validate the roadmap approach of entecavir switch therapy in patients with incomplete response to telbivudine.
  
  
  METHODS
  Consecutive chronic hepatitis B patients on telbivudine monotherapy were studied. Incomplete virological response was defined as detectable HBV DNA after 6-12 months of treatment. Maintained virological response was defined as undetectable HBV DNA until the last follow-up.
  
  
  RESULTS
  Among the 79 patients on telbivudine, 39 (49%) had undetectable HBV DNA after 6-12 months of telbivudine treatment and 40 (51%) had incomplete virological response. In total, 33 incomplete responders switched to entecavir at 11 months (6-23), and 26 (79%) achieved maintained virological response after 25 months (4-46). Low HBV DNA level before switch therapy was the independent factor associated with maintained virological response to entecavir (P=0.01). A total of 24 of 25 (96%) patients with HBV DNA<2,000 IU/ml, versus 2 of 8 (25%) patients with HBV DNA≥2,000 IU/ml, had maintained virological response after switching to entecavir. Although rtM204I and/or rtL180M was detected in 3 of 7 patients with incomplete virological response to entecavir, none of the patients with HBV DNA<2,000 IU/ml during telbivudine treatment harboured these amino acid substitutions.
  
  
  CONCLUSIONS
  Roadmap approach using entecavir switch at month 6-12 among incomplete responders to telbivudine is recommended if the HBV DNA is <2,000 IU/ml at the time of switching.
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, Hong Kong.
authors: Angeline Oi-Shan
authors: AO
authors: Lo
authors: Vincent Wai-Sun
authors: VW
authors: Wong
authors: Grace Lai-Hung
authors: GL
authors: Wong
authors: Hoi-Yun
authors: HY
authors: Chan
authors: Christina Man-Tung
authors: CM
authors: Cheung
authors: Henry Lik-Yuen
authors: HL
authors: Chan
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D024882:Drug Resistance, Viral; D057915:Drug Substitution; D005260:Female; D005500:Follow-Up Studies; D006147:Guanine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006515:Hepatitis B virus / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D012189:Retrospective Studies; D012307:Risk Factors; D000077712:Telbivudine; D013936:Thymidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D000077712:Telbivudine; C413685:entecavir; D006147:Guanine; D013936:Thymidine