Effect of Multiple Doses of Sparsentan on the Single-Dose Pharmacokinetics of Dapagliflozin: An Open-Label Drug-Drug Interaction Study in Healthy Adults.

Sparsentan is a single-molecule dual antagonist of the endothelin type A receptor and angiotensin II type 1 receptor under investigation for the treatment of focal segmental glomerulosclerosis and immunoglobulin A nephropathy. Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, has recently been indicated in chronic kidney disease. Sparsentan may be considered for concomitant use with dapagliflozin. The purpose of this open-label, 1-sequence crossover study was to determine whether drug-drug interactions between sparsentan and dapagliflozin affect dapagliflozin pharmacokinetics (PK). In addition, exposure to the inactive metabolite of dapagliflozin, dapagliflozin-3-O-glucuronide, was used to evaluate the effect of sparsentan on the primary metabolizing enzyme of dapagliflozin, uridine 5'-diphospho-glucuronosyltransferase 1A9. The study included 22 healthy adults treated with 10 mg of dapagliflozin on day 1, and 800 mg/day of sparsentan on days 5-14, with a 10-mg dose of dapagliflozin coadministered on day 11. PK samples were taken for dapagliflozin, dapagliflozin-3-O-glucuronide, and sparsentan before and after treatment throughout the study. Steady-state concentrations of sparsentan following daily dosing did not affect the PK of single-dose dapagliflozin in healthy adults. Dapagliflozin-3-O-glucuronide PK suggests a minimal effect of sparsentan on metabolism of dapagliflozin by uridine 5'-diphospho-glucuronosyltransferase 1A9. No deaths, serious adverse events, or unusual safety signals occurred. Results suggest dapagliflozin PK is not affected by sparsentan daily dosing.