title: Extended treatment with lamivudine and adefovir dipivoxil in chronic hepatitis B patients with lamivudine resistance.
abstract: OBJECTIVE
  We and others have reported that adding adefovir dipivoxil (adefovir) to lamivudine results in virological and biochemical improvement in cases of lamivudine resistance. The current study assessed the efficacy and safety of combined therapy after 104 weeks of combined treatment and analyzed the frequency of persistent lamivudine resistant HBV.
  
  
  METHODS
  A total of 78 patients with compensated CHB (Group A) were maintained on either adefovir 10 mg daily (n = 38) or placebo (n = 40) while continuing lamivudine. An additional 38 patients with decompensated cirrhosis or post liver transplantation (Group B) received lamivudine plus adefovir. The primary endpoint was HBV DNA response at year 2.
  
  
  RESULTS
  At week 104 of therapy, a significantly greater proportion of patients in Group A on combination therapy (76%) had a decline in serum HBV DNA to ≤10(5) copies or >2 log(10) reduction from baseline compared to those receiving lamivudine alone (13%; p < 0.001). Fifty-two percent of Group A patients on combination treatment continued to have the M204V/I HBV mutation compared to 92% receiving lamivudine alone (p = 0.0013). Virologic response occurred less frequently in patients expressing persistent lamivudine resistant HBV. In Group B, 87% of patients had HBV DNA response at week 104 (median change from baseline of -5.84 log(10) copies/mL).
  
  
  CONCLUSIONS
  The combination of lamivudine and adefovir for 2 years generally proved effective in lamivudine-resistant cases, but there was a persistently high rate of detection of lamivudine resistant mutants and impaired virologic response in compensated patients.
authors.affiliation: Baylor University Medical Center, Dallas, TX, USA, roberper@baylorhealth.edu.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Perrillo
authors.forename: Hie-Won
authors.initials: HW
authors.lastname: Hann
authors.forename: Eugene
authors.initials: E
authors.lastname: Schiff
authors.forename: David
authors.initials: D
authors.lastname: Mutimer
authors.forename: Bernard
authors.initials: B
authors.lastname: Willems
authors.forename: Nancy
authors.initials: N
authors.lastname: Leung
authors.forename: William M
authors.initials: WM
authors.lastname: Lee
authors.forename: Susan
authors.initials: S
authors.lastname: Dixon
authors.forename: Mary
authors.initials: M
authors.lastname: Woessner
authors.forename: Carol L
authors.initials: CL
authors.lastname: Brosgart
authors.forename: Lynn D
authors.initials: LD
authors.lastname: Condreay
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Gardner