LAUSR

Absolute bioavailability (F) and the impact of gastric pH, tablet formulation, and food on the pharmacokinetics and safety of asundexian, an oral factor XIa inhibitor, was assessed in healthy White men aged 18–45 years in 4 studies. For F, fasted participants received 50 μg of [13C7,15N]‐labeled asundexian intravenously 2 hours after 25 mg of asundexian orally. Tablet formulation (50‐mg immediate release [IR], and different amorphous solid dispersion [ASD] IR 25‐mg and 50‐mg ASD IR tablets) and food effects were explored in 2 studies. Formulation was compared using 50‐mg IR versus 25‐mg ASD IR and 25‐mg ASD IR versus 50‐mg ASD IR (fasted); food effect using 25‐mg ASD IR and 50‐mg ASD IR. Gastric pH modulation was assessed using omeprazole or antacid coadministration with asundexian in the fasted state. Pharmacokinetic parameters included area under the concentration‐time curve (AUC; and AUC/dose [D]) and maximum observed concentration (Cmax and Cmax/D) data were evaluable for 59 participants. F was 103.9%. Relative bioavailability with 25‐mg ASD IR and 50‐mg ASD IR tablets, respectively, was marginally affected by formulation (AUC/D ratios, 94.3% and 95.1%; Cmax/D ratios, 95.5% and 88.7%), food (AUC[/D] ratios, 91.1% and 96.9%; Cmax[/D] ratios: 78.3% and 95.1%), and gastric pH (omeprazole, no effect; antacid, AUC ratio, 89.9% and Cmax ratio, 83.7%). No serious adverse events or deaths occurred; most adverse events were mild or moderate. In summary, oral asundexian was well tolerated and demonstrated complete bioavailability irrespective of tablet formulation, food, or gastric pH.