Maintaining remission in lamivudine-resistant patients with a virological response to adefovir add-on lamivudine after stopping lamivudine therapy

Background & AimsWe examined the durability of the virological response after discontinuing lamivudine (LVD) in chronic hepatitis B (CHB) patients with LVD-resistant hepatitis B virus (HBV), who responded to LVD plus adefovir (ADV) combination therapy, and the outcome of switching to ADV monotherapy compared to maintaining combination therapy. MethodsThis study enrolled 72 patients with undetectable viral loads (12IU/ml) and normal alanine aminotransferase levels after ADV add-on therapy for at least 6months in LVD-resistant CHB patients. The enrolled patients were randomly assigned to continue with LVD-ADV combination therapy or switch to ADV monotherapy (n=36 per group). Virological rebound was defined as HBV DNA detection at more than 12IU/ml by quantitative polymerase chain reaction determined on two consecutive measurements. ResultsDuring 96weeks of follow-up, 100% (36/36) of the patients in the LVD-ADV combination maintained group had persistently undetectable HBV DNA, compared with 94.4% (34/36) patients in the ADV monotherapy switched group. These two patients had undetectable HBV DNA after switching back to LVD-ADV combination therapy. There were no significant differences in the HBsAg levels between the two treatment groups during the 96-week follow-up period. ConclusionsIn our study, switching to ADV monotherapy resulted in sustained HBV DNA suppression in 94.4% of the patients for 96weeks. Prior complete viral suppression with LVD-ADV combination therapy conferred a significant advantage in patients who switched to ADV monotherapy. LVD may be discontinued in patients who show a complete virological response to LVD-ADV combination therapy for at least 6months.