title: Efficacy of tenofovir in adefovir-experienced patients compared with treatment-naive patients with chronic hepatitis B.
abstract: BACKGROUND
  Tenofovir (TDF) has similar antiviral efficacy in both treatment-naive and lamivudine-resistant chronic hepatitis B (CHB) patients. Data on TDF use in patients with adefovir (ADV) resistance is inconsistent. The aim of our study was to assess antiviral efficacy of TDF against nucleoside analogue-naive (NN) and ADV-resistant (ADV-R) CHB and suboptimal responders to ADV (ADV-S).
  
  
  METHODS
  A database of 135 CHB patients treated with TDF was analysed. A total of 37 patients with incomplete data were excluded and analysis was performed in 98 (44 NN, 30 ADV-R and 24 ADV-S). Patients with primary ADV-R mutations had either A181T/V or N236T mutations or both. HBV DNA was measured at 3-month intervals until month 24. Primary outcome measures were comparison of the decline of HBV DNA between the three treatment groups.
  
  
  RESULTS
  NN patients had higher baseline HBV DNA compared with ADV-R and ADV-S patients (6.08 log10 IU/ml versus 5.53 and 4.88, respectively; P=0.002). By exponential regression analysis, HBV DNA decline kinetics differed between the three groups. HBV DNA decline was faster in NN patients compared to ADV-R and ADV-S CHB patients (P=0.002 and P=0.004, respectively). Undetectable HBV DNA was achieved in 77.2%, 60% and 75% of NN, ADV-R and ADV-S CHB patients, respectively, at month 12 (P= not significant).
  
  
  CONCLUSIONS
  HBV DNA decline is slower in ADV-experienced patients compared with treatment-naive patients. The clinical significance of this slow response may be important in patients with critical liver reserve and high viral load. Optimal combination treatment (TDF+ entecavir) could be considered in these patients.
authors: Department of Gastroenterology, University of Ankara Medical School, Ankara, Turkey.
authors: Onur
authors: O
authors: Keskin
authors: Asli C
authors: AC
authors: Ormeci
authors: Bülent
authors: B
authors: Baran
authors: Gökhan
authors: G
authors: Kabaçam
authors: Ali
authors: A
authors: Tüzün
authors: Ersin
authors: E
authors: Karatayli
authors: Filiz
authors: F
authors: Akyüz
authors: Senem
authors: S
authors: Karatayli
authors: A Mithat
authors: AM
authors: Bozdayi
authors: Derya
authors: D
authors: Onel
authors: Selim
authors: S
authors: Badur
authors: Ramazan
authors: R
authors: Idilman
authors: Sabahattin
authors: S
authors: Kaymakoglu
authors: Cihan
authors: C
authors: Yurdaydin
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000627:therapeutic use*; D004279:DNA, Viral; D024882:Drug Resistance, Viral; D005260:Female; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000627:therapeutic use*; D019233:Retreatment; D012189:Retrospective Studies; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D000068698:Tenofovir; D013997:Time Factors; D016896:Treatment Outcome; D019562:Viral Load; D055815:Young Adult
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors; C053001:adefovir; D000068698:Tenofovir; D000225:Adenine