[Efficacy of tenofovir-based rescue therapy for patients with drug-resistant chronic hepatitis B].

BACKGROUND/AIMS: Tenofovir disoproxil fumarate (TDF) plays a pivotal role in the management of drug-resistant chronic hepatitis B. However, it remains unclear whether TDF-nucleoside analogue combination therapy provides better outcomes than TDF monotherapy. This study aimed to compare the efficacy of TDF monotherapy with that of TDF-nucleoside analogue combination therapy in patients with drug-resistant chronic hepatitis B.
METHODS: This retrospective cohort study included 76 patients receiving TDF-based rescue therapy for more than 12 months. Suboptimal response was defined as serum HBV-DNA level of > 60 IU/mL during prior rescue therapy. Multi-drug resistance was defined as the presence of two or more drug resistance-related mutations confirmed by mutation detection assay. The relationship between baseline characteristics and virologic response (HBV DNA < 20 IU/mL) at 12 months were evaluated using logistic regression analysis.
RESULTS: Fifty-five patients (72.4%) were suboptimal responders to prior rescue therapy, and 26 (34.2%) had multi-drug resistance. Forty-two patients (55.3%) received combination therapy with nucleoside analogues. Virologic response at 12 months was not significantly different between the TDF monotherapy group and TDF-nucleoside analogue combination therapy group (p = 0.098). The serum HBV DNA level was reduced to -4.49 ± 1.67 log10 IU/mL in the TDF monotherapy group and to -3.97 ± 1.69 log10 IU/mL in the TDF-nucleoside analogue combination therapy group at 12 months (p = 0.18). In multivariate analysis, female sex (p = 0.032), low baseline HBV-DNA level (p = 0.013), and TDF monotherapy (p = 0.046) were predictive factors for virologic response at 12 months.
CONCLUSIONS: TDF monotherapy showed similar efficacy to that of TDF-nucleoside analogue combination therapy in patients with drug-resistant chronic hepatitis B.