title: Comparison of tenofovir plus lamivudine versus tenofovir monotherapy in patients with lamivudine-resistant chronic hepatitis B.
abstract: OBJECTIVE
  Tenofovir disoproxil fumarate (TDF) exhibits similar antiviral efficacy against treatment-naïve and lamivudine (LAM)-resistant chronic hepatitis B (CHB). However, there are few clinical reports on the antiviral effects of TDF-LAM combination therapy compared to TDF monotherapy in patients with LAM-resistant CHB.
  
  
  METHODS
  We investigated the antiviral efficacy of TDF monotherapy vs. TDF-LAM combination therapy in 103 patients with LAM-resistant CHB.
  
  
  RESULTS
  The study subjects were treated with TDF alone (n=40) or TDF-LAM combination therapy (n=63) for ≥6 months. The patients had previously been treated with TDF-based rescue therapy for a median of 30.0 months (range, 8-36 months). A virologic response (VR) was achieved in 99 patients (96.1%): 95.0% (38/40) of patients in the TDF monotherapy group and 96.8% (61/63) of patients in the TDF-LAM combination therapy group. The VR rates were not significantly different between the TDF monotherapy and TDF-LAM combination therapy groups (88.9 vs. 87.3% at month 12, and 94.4 vs. 93.7% at month 24, log-rank p=0.652). Univariate and multivariate analyses revealed that none of the pretreatment factors were significantly associated with VR.
  
  
  CONCLUSIONS
  TDF monotherapy was as effective as TDF-LAM combination therapy for maintaining viral suppression in the vast majority of patients with LAM-resistant CHB, which suggests that TDF add-on therapy with LAM is unnecessary.
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Chan Ho
authors.initials: CH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Jung Woo
authors.initials: JW
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Mi Ae
authors.initials: MA
authors.lastname: Bae
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Yoon Im
authors.initials: YI
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Yong Tae
authors.initials: YT
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Hwa Sik
authors.initials: HS
authors.lastname: Chung
authors.affiliation: Department of Internal Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
authors.forename: Neung Hwa
authors.initials: NH
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood; D004334:Drug Administration Schedule; D024882:Drug Resistance, Viral / Q000187:drug effects; D004359:Drug Therapy, Combination; D005260:Female; D006515:Hepatitis B virus / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D007677:Kidney Function Tests; D019259:Lamivudine / Q000627:therapeutic use*; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D000068698:Tenofovir / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D019259:Lamivudine; D000068698:Tenofovir
keywords: Chronic hepatitis B; Lamivudine; Resistance; Tenofovir