Absolute oral bioavailability of milvexian spray‐dried dispersion formulation under fasted and fed conditions in healthy adult participants: An intravenous microtracer approach

Milvexian is an oral, small-molecule factor XIa inhibitor being developed to prevent thromboembolic events. This study assessed the absolute bioavailability (F) of milvexian following single doses of milvexian spray-dried dispersion (SDD) formulation under fed and fasted conditions, and milvexian solution, in healthy adult participants using an intravenous microtracer approach. This was a phase I, open-label, partially randomized, 4-sequence, 5-period crossover study. After fasting for ≥10 h, participants received milvexian 200-mg oral solution with a 100-μg ¹⁴C milvexian intravenous microtracer at the time of maximum observed plasma concentration. Following a 3-day washout, participants were randomized to 1 of 4 milvexian SDD treatment sequences in a crossover fashion: 25 mg fasted, 25 mg fed, 200 mg fasted, or 200 mg fed. Pharmacokinetic data were collected up to 72 h postdose. Seventeen participants were dosed, and 14 completed treatment. Under fasted conditions, milvexian F was ~100%, 58.2%, and 54.2% following administration of the oral solution, 25 mg SDD, and 200 mg SDD, respectively. Under fed conditions, milvexian F following 25 mg and 200 mg SDD was 44.3% and 75.6%, respectively. The milvexian SDD formulation at 25 mg and 200 mg resulted in similar F in a fasted state; under fed conditions, milvexian F decreased at 25 mg and increased at 200 mg. These findings clarify pharmacokinetic-related gaps observed in previous studies.