Factor XIa inhibitors milvexian and asundexian, hailed as the next-generation class of anticoagulants, earned mixed reviews on phase II data presented during the European Society of Cardiology Congress 2022. However, developers Bristol Myers Squibb Co./Janssen Pharmaceutical Co. and Bayer AG, respectively, are moving into late-stage testing, citing clear mechanisms of action that put the FXIa drugs at least on par with approved factor Xa drugs in terms of efficacy while offering potentially better safety profiles that could give physicians an option for patients with stroke or atrial fibrillation who are currently undertreated with anticoagulants due to bleeding risks.