Background/aim: There is very limited experience in the management of telbivudine (LdT)-associated virological breakthrough (VBT) and resistance in the treatment of chronic hepatitis B (CHB) patients, and the guideline recommendations are primitively based on the general principles of rescue therapy to nucleos(t)ide analog resistance. The aim of this study is to determine the effect of the addition of adefovir (ADV) in hepatitis B e antigen (HBeAg)-positive CHB patients with VBT or resistance to LdT.
Methods: Thirty-seven CHB patients with confirmed VBT and 31 patients with genotypic resistance to LdT were enrolled and thereafter treated with a combination of LdT and ADV for 12 months.
Results: Combination therapy was safe and the majority of patients tolerated the therapy. LdT+ADV led to rapid decreases in viral loads, and viral replications were persistently suppressed, with 2.17 (VBT) and 2.31 (resistance) log(10) copies/ml reductions 12 months after rescue therapy, respectively. The rates corresponding to virological and biochemical responses were similar between the two groups at the end of observations (70.3 vs. 74.2% for virological response, P=0.720; 64.0 vs. 65.5% for biochemical response, P=0.907). The cumulative rates of serological responses were higher in patients with VBT than in those with resistance (35.1 vs. 9.67% for HBeAg loss, P=0.014; 10.8 vs. 3.23% for HBeAg/anti-HBe seroconversion, P=0.233).
Conclusion: LdT and ADV combination therapy led to significant decreases in serum hepatitis B virus DNA levels and normalization of alanine aminotransferase levels in patients with VBT or genotypic resistance to LdT. This rescue strategy was also associated with a higher rate of HBeAg serological outcomes in patients with confirmed LdT-related VBT.