Tenofovir Alafenamide Versus Entecavir as Switch Therapy After Tenofovir Disoproxil Fumarate in Patients with Chronic Hepatitis B.

Background: Tenofovir alafenamide (TAF) and entecavir (ETV) are recommended alternatives to tenofovir disoproxil fumarate (TDF) for patients with chronic hepatitis B (CHB) at increased risk of kidney injury. However, data from direct head-to-head comparisons of their long-term renal safety and antiviral efficacy after switching from TDF are lacking. We aimed to compare these outcomes between TAF and ETV. Methods: This multicenter retrospective cohort study included consecutive CHB patients who switched from TDF to either TAF or ETV between January 2012 and December 2021. Inverse probability of treatment weighting using the propensity score was applied to balance the baseline characteristics. Changes in estimated glomerular filtration rate (eGFR) were assessed using a linear mixed-effects model. Renal dysfunction was defined as a decline of at least one GFR category. Results: A total of 235 patients were included (TAF, n = 168; ETV, n = 67). After adjustment for key risk factors, the mean eGFR decline over 36 months was not significantly different between the TAF and ETV groups (-3.21 mL/min/1.73 m2 [95% CI, -4.98 to -1.44] vs. -3.49 mL/min/1.73 m2 [95% CI, -9.49 to -2.50]; p = 0.856). The 3-year cumulative incidence of renal dysfunction was also not significantly different between groups (16.6% [95% CI, 10.5-23.3] vs. 7.8% [95% CI, 2.7-16.2]; p = 0.135). Alanine aminotransferase normalization rates (83.0% vs. 78.8%; p = 0.575) and virological suppression rates (97.8% vs. 97.1%; p = 1.000) were similarly high in both groups. Conclusions: TAF and ETV demonstrated similar long-term renal safety and antiviral efficacy, supporting both agents as reasonable switch options for CHB patients requiring TDF discontinuation because of renal safety concerns.