What Is the Future of Factor XI Inhibitors?

Parenteral and oral factor XI (FXI) inhibitors, the next potential generation of anticoagulants, are undergoing phase-3 evaluation with the hope that they will be safer than currently available agents.1 This article (1) addresses the unmet needs in anticoagulation therapy; (2) explains why FXI may be more important for thrombosis than for hemostasis; (3) identifies the FXI inhibitors in advanced stages of development; (4) describes the results of the phase 2 trials; and (5) provides perspective on the opportunities and challenges for this new class of anticoagulants.