[Safety profile of tenofovir amibufenamide therapy extension or switching in patients with chronic hepatitis B: a phase Ⅲ multicenter, randomized controlled trial].

Objective: In chronic hepatitis B (CHB) patients with previous 96-week treatment with tenofovir amibufenamide (TMF) or tenofovir disoproxil fumarate (TDF), we investigated the safety profile of sequential TMF treatment from 96 to 144 weeks. Methods: Enrolled subjects that previously assigned (2:1) to receive either 25 mg TMF or 300 mg TDF with matching placebo for 96 weeks received extending or switching TMF treatment for 48 weeks. Safety profiles of kidney, bone, metabolism, body weight, and others were evaluated. Results: 666 subjects from the initial TMF group and 336 subjects from TDF group with at least one dose of assigned treatment were included at week 144. The overall safety profile was favorable in each group and generally similar between extended or switched TMF treatments from week 96 to 144. In subjects switching from TDF to TMF, the non-indexed estimated glomerular filtration rate (by non-indexed CKD-EPI formula) and creatinine clearance (by Cockcroft-Gault formula) were both increased, which were (2.31±8.33) ml/min and (4.24±13.94) ml/min, respectively. These changes were also higher than those in subjects with extending TMF treatment [(0.91±8.06) ml/min and (1.30±13.94) ml/min]. Meanwhile, switching to TMF also led to an increase of the bone mineral density (BMD) by 0.75% in hip and 1.41% in spine. On the other side, a slight change in TC/HDL ratio by 0.16 (IQR: 0.00, 0.43) and an increase in body mass index (BMI) by (0.54±0.98) kg/m² were oberved with patients switched to TMF, which were significantly higher than that in TMF group. Conclusion: CHB patients receiving 144 weeks of TMF treatment showed favorable safety profile. After switching to TMF, the bone and renal safety was significantly improved in TDF group, though experienceing change in metabolic parameters and weight gain (NCT03903796).