Systematic review and model-based analysis to identify whether renal safety risks of URAT1 inhibitors are fully determined by uric acid-lowering efficacies.

Objective: Renal safety risk is currently an important factor that hinders the development of uric acid transporter 1 (URAT1) inhibitors. This study aimed to compare the renal safety and uric acid-lowering efficacy of different URAT1 inhibitors and clarify the association between them.

Methods: A systematic review of published randomized controlled trials on URAT1 inhibitors was conducted to investigate the incidence of renal safety events. A model-based analysis was performed to predict the uric acid-lowering efficacy of representative URAT1 inhibitors.

Results: The overall renal safety event incidences of lesinurad, verinurad, dotinurad, SHR4640, and benzbromarone in patients with hyperuricemia were 11.2 % (142/1264), 12.0 % (34/284), 0.5 % (2/421), 2.3 % (5/213), and 1.3 % (5/393), respectively. A semi-mechanistic pharmacokinetic/pharmacodynamic model was used to establish the dose-exposure-effect relationship of lesinurad, verinurad, dotinurad, and SHR4640 with or without the combination of xanthine oxidase inhibitors (XOIs). The efficacy ranking of the intermediate dose of URAT1 inhibitors with once-daily dosing was 2 mg dotinurad > 10 mg verinurad > 5 mg SHR4640 > 400 mg lesinurad. The combination of 80 mg febuxostat and 600 mg allopurinol reduced the 24-h cumulative renal uric acid excretion by 48.4 % and 48.3 %, respectively.

Conclusion: Uric acid-lowering efficacy is not an independent factor for the renal safety risk of different URAT1 inhibitors, and structural differences could be responsible for the difference. The adverse renal effects of URAT1 inhibitors are dose-dependent, and the combination with high doses of XOIs can significantly reduce the renal safety risk by reducing uric acid excretion by the kidneys.