molecules of the month

asundexian (BAY2433334) is a reversible Factor XIa active site inhibitor previously disclosed at the 2021 EFMC-ISMC conference. This article highlights the Ph. I data of asundexian in healthy volunteers, showing that the drug is well tolerated, with no clinically relevant bleeding-related adverse events or any relevant CYP3A4 modulation. The molecule is suitable for once daily dosing (20, 50 mg PO QD), and is currently being tested in more than 4000 patients in several phase 2 studies (NCT04304534, NCT04510987, NCT04304508, NCT04218266). This program follows Bayer’s success with rivaroxaban (Factor Xa inhibitor), another key target in the coagulation cascade. In contrast to factor Xa, factor XIa is not required for homeostasis. The molecule’s discovery story has not been published yet (conference report only, patent: US10421742B2). This chemical…