Treatment of lamivudine-resistant chronic hepatitis B infection: a multicenter retrospective study

Objectives. To compare the efficacy of rescue therapies in lamivudine (LAM)-resistant chronic hepatitis B (CHB) infections including: (1) adefovir dipivoxil (ADV) monotherapy, (2) ADV plus LAM combination therapy and (3) entecavir (ETV) 1.0 mg monotherapy. Materials and methods. The authors designed a multicenter-retrospective study. Eight institutions participated in the study from Korea. Results. A total of 343 LAM-resistant CHB patients were enrolled. The proportion of patients with undetectable serum hepatitis B virus (HBV) DNA levels at month 24 after the initiation of rescue therapy was higher in the ADV plus LAM combination therapy group (39/64, 60.9%) than in the ADV monotherapy (50/126, 39.7%) and ETV 1.0 mg monotherapy (19/48, 39.6%) groups (p = 0.014). Mean serum HBV DNA levels at 24 months were 2.07 +/- 1.21 log(10) IU/ml in the ADV plus LAM combination therapy group, 2.74 +/- 1.74 log(10) IU/ml in the ADV monotherapy group and 3.08 +/- 1.97 log(10) IU/ml in the ETV 1.0 mg monotherapy group (p = 0.014). In multivariate analysis, a finding of undetectable serum HBV DNA level at 6 months and ADV plus LAM combination therapy (vs. ADV) was an independent factor for predicting undetectable serum HBV DNA at month 24 (odds ratio, 1.003; 95% confidence interval, 1.000-1.006; p = 0.026). Conclusions. ADV plus LAM combination therapy is more effective in reducing viral load than switching to ADV or ETV 1.0 mg in patients with LAM-resistant CHB.