Differential Relapse Patterns After Discontinuation of Entecavir vs Tenofovir Disoproxil Fumarate in Chronic Hepatitis B

BACKGROUND AND AIMS: Whether entecavir (ETV) and tenofovir disoproxil fumarate (TDF) differentially affect relapse and outcomes following treatment discontinuation across different patient subpopulations remains unclear. We aimed to compare rates of off-therapy hepatitis B surface antigen (HBsAg) loss, virological and clinical relapse, and retreatment between chronic hepatitis B (CHB) pa-tients who discontinued TDF or ETV therapy.METHODS: This study included 1402 virally suppressed CHB patients who stopped either ETV (n = 981) or TDF (n = 421) therapy between 2001 and 2020 from 13 participating centers across North America, Europe, and Asia. All patients were hepatitis Be antigen-negative at treatment discontinuation. Inverse probability of treatment weighting was used to balance the treatment groups. Outcomes were analyzed using survival methods.RESULTS: During a median off-treatment follow-up of 18 months, HBsAg loss occurred in 96 (6.8%) pa-tients overall. Compared with ETV, TDF was associated with a higher rate of HBsAg loss (P = .03); however, the association was no longer significant after statistical adjustment (P = .61). Virological relapse occurred earlier among TDF-treated patients (P < .01); nonetheless, rates became comparable after the first year off therapy (P = .49). TDF was significantly associated with a higher clinical relapse rate than ETV throughout follow-up (P < .01). The development of a virological or clinical relapse did not affect the rate of HBsAg loss. Retreatment rates were not significantly different between the treatment groups.CONCLUSIONS: TDF and ETV have differential relapse patterns but are associated with similar rates of HBsAg loss and retreatment following discontinuation. Finite therapy can be considered for CHB pa- tients on either TDF or ETV therapy.

Automated summary

This study compared the relapse rates and treatment outcomes after discontinuation of therapy in chronic hepatitis B patients using entecavir (ETV) and tenofovir disoproxil fumarate (TDF). It found that TDF was associated with a higher rate of HBsAg loss, earlier virological relapse, and higher clinical relapse compared to ETV. However, the rates of HBsAg loss and retreatment were similar between the two treatment groups. Finite therapy can be considered for CHB patients on either TDF or ETV therapy.