Early virological suppression is associated with good maintained response to adefovir dipivoxil in lamivudine resistant chronic hepatitis B

Aim To determine the factors affecting the virological response to adefovir dipivoxil (ADV) among patients with lamivudine resistant chronic hepatitis B. Methods Chronic hepatitis B virus (HBV) infected patients, who had virological relapse to lamivudine, were switched to ADV monotherapy. Results Twenty-six patients were treated by ADV for 23 (12-41) months. At baseline, the median log HBV DNA was 7.70 (4.88-9.01) copies/mL. Six (23%) and 8 (31%) of patients had HBV DNA suppressed to below 1000 copies/mL at month 12 and the last follow-up, respectively. On linear regression, patients who had higher HBV DNA at baseline and month 6 have higher HBV DNA at month 12. On Cox proportional hazard model, the hazard ratio for each log step increase in HBV DNA at baseline and month 6 for HBV DNA < 1000 copies/mL at the last visit was 0.39 (P = 0.010) and 0.47 (P = 0.027), respectively. Alanine aminotransferase, HBV genotype, rtL80 M mutation and log HBsAg did not affect the HBV DNA response. Conclusions The response of lamivudine-resistant patients to ADV is suboptimal. Treatment with ADV when HBV DNA is low, and rapid viral suppression at month 6 increases the chance of maintained viral suppression.