Tenofovir amibufenamide in chronic hepatitis B: Lipid changes and 144-week safety with tenofovir disoproxil fumarate-to-tenofovir amibufenamide switch

BACKGROUND Tenofovir amibufenamide (TMF) has shown antiviral efficacy comparable to tenofovir disoproxil fumarate (TDF) in chronic hepatitis B (CHB), with improved renal and bone safety profiles. While TDF is recognized for its lipid-lowering properties, the long-term effects of TMF on lipid metabolism remain unclear. AIM To assess lipid changes and long-term safety of TMF in CHB, including outcomes after TDF-to-TMF switch over 144 weeks. METHODS This retrospective analysis utilized data from a phase III randomized, double-blind trial involving 53 patients with CHB treated with either TMF 25 mg (n = 39) or TDF 300 mg (n = 14) once daily for 96 weeks. Following this blinded phase, all participants entered an open-label extension in which they received TMF until week 144. This design enabled assessment of both the comparative effects of TMF and TDF and the impact of switching from TDF to TMF, thereby reflecting real-world treatment scenarios. Virological, biochemical and imaging evaluations were performed throughout the study. RESULTS At week 96, both groups achieved comparable virological suppression and maintained stable hepatic and renal function. However, total cholesterol and low-density lipoprotein cholesterol levels were significantly higher in the TMF group compared to the TDF group (P = 0.012 and P = 0.040, respectively). TDF was associated with a transient increase in serum phosphate (P = 0.030). After switching to TMF, lipid profiles in the former TDF group gradually aligned with those of the continuous TMF group by week 144, with no lipid abnormalities observed in either group. CONCLUSION TMF provides sustained antiviral efficacy and maintains a favourable long-term lipid and renal safety profile. These findings support TMF as a viable first-line therapy and a switch option for CHB management in clinical practice.