96-Week Treatment of Tenofovir Amibufenamide and Tenofovir Disoproxil Fumarate in Chronic Hepatitis B Patients.

Background and Aims: Tenofovir amibufenamide (TMF) is a novel phosphoramidated prodrug of tenofovir with noninferior efficacy and better bone and renal safety to tenofovir disoproxil fumarate (TDF) in 48 weeks of treatment. Here, we update 96-week comparison results. Methods: Patients with chronic hepatitis B were assigned (2:1) to receive either 25 mg TMF or 300 mg TDF with matching placebo for 96 weeks. The virological suppression was defined as HBV DNA levels <20 IU/mL at week 96. Safety was evaluated thoroughly with focusing on bone, renal, and metabolic parameters. Results: Virological suppression rates at week 96 were similar between TMF and TDF group in both HBeAg-positive and HBeAg-negative populations. Noninferior efficacy was maintained in the pooled population, while it was first achieved in patients with HBV DNA ≥7 or 8 log10 IU/mL at baseline. Non-indexed estimated glomerular filtration rate for renal safety assessment was adopted, while a smaller decline of which was seen in the TMF group than in the TDF group (p=0.01). For bone mineral density, patients receiving TMF displayed significantly lower reduction levels in the densities of spine, hip, and femur neck at week 96 than those receiving TDF. In addition, the lipid parameters were stable after week 48 in all groups while weight change still showed the opposite trend. Conclusions: TMF maintained similar efficacy at week 96 compared with TDF with continued superior bone and renal safety profiles (NCT03903796).