title: A short course of add-on adefovir dipivoxil treatment in lamivudine-resistant chronic hepatitis B patients.
abstract: The aims of the study were to investigate the efficacy of rescue therapy with lamivudine (LAM) and adefovir (ADV) combination for 6 months followed by ADV monotherapy in lamivudine-resistant chronic hepatitis B (LAM-R CHB) patients, and to analyze the frequency of ADV resistance mutant development in such patients. A total of 170 consecutive LAM-R CHB patients (male/female: 130/40, mean age: 42.9+/-13.4 years) with viral breakthrough under LAM therapy were analyzed. A total of 68 had HBeAg-positive. Patients received rescue therapy with LAM [100 mg (qd)]+ADV [10 mg (qd)] for 6 months after which LAM was discontinued. HBV-DNA was assessed with the HBV-DNA 3.0 bDNA assay. ADV-resistant mutations were identified by sequencing the reverse transcriptase region. The median duration of rescue therapy was 24 months. Cumulative probability of becoming HBV-DNA undetectable was 33.8%, 59.6% and 68.2% after 24, 48 and 96 weeks of treatment, respectively. These figures were 43.2%, 58.0% and 73.1% for ALT normalization. Among 68 HBeAg-positive CHB patients, 10 patients had an e-antigen seroconversion. Low baseline HBV-DNA level (<10(7) copies/mL) was a significant predictor of response to ADV treatment (P<0.01). Cumulative probability of ADV resistance was 1.2%, 15.1% and 37.3% at 12, 24 and 36 months of therapy, respectively. By multivariate analysis, baseline high viral load and primary nonresponse to treatment at week 24 predicted ADV resistance. The data indicate that a time limited add-on strategy does not provide benefit over the switch strategy with respect emergence of ADV resistant mutants in LAM-R CHB patients.
authors.affiliation: Department of Gastroenterology, Faculty of Medicine, Ankara University, Ankara, Turkey. idilman@medicine.ankara.edu.tr
authors.forename: R
authors.initials: R
authors.lastname: Idilman
authors.forename: S
authors.initials: S
authors.lastname: Kaymakoglu
authors.forename: F
authors.initials: F
authors.lastname: Oguz Onder
authors.forename: E
authors.initials: E
authors.lastname: Ahishali
authors.forename: M
authors.initials: M
authors.lastname: Bektas
authors.forename: K
authors.initials: K
authors.lastname: Cinar
authors.forename: B
authors.initials: B
authors.lastname: Pinarbasi
authors.forename: S
authors.initials: S
authors.lastname: Karayalcin
authors.forename: S
authors.initials: S
authors.lastname: Badur
authors.forename: Y
authors.initials: Y
authors.lastname: Cakaloglu
authors.forename: A
authors.initials: A
authors.lastname: Mithat Bozdayi
authors.forename: H
authors.initials: H
authors.lastname: Bozkaya
authors.forename: A
authors.initials: A
authors.lastname: Okten
authors.forename: C
authors.initials: C
authors.lastname: Yurdaydin
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D000328:Adult; D019943:Amino Acid Substitution / Q000235:genetics; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004279:DNA, Viral / Q000097:blood / Q000235:genetics; D024882:Drug Resistance, Viral; D005260:Female; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects; D019694:Hepatitis B, Chronic / Q000188:drug therapy*; D006801:Humans; D019259:Lamivudine / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D063065:Organophosphonates / Q000494:pharmacology / Q000627:therapeutic use*; D016879:Salvage Therapy / Q000379:methods; D017422:Sequence Analysis, DNA; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D004279:DNA, Viral; D006513:Hepatitis B e Antigens; D063065:Organophosphonates; D019259:Lamivudine; D000225:Adenine; C106812:adefovir dipivoxil