Background Andexanet alfa (andexanet) is a recombinant modified human factor Xa decoy
protein that has been shown to reverse the inhibition of factor Xa in healthy volunteers.
Methods In this multicenter, prospective, open-label, single-group study, we evaluated 67
patients who had acute major bleeding within 18 hours after the administration of a factor Xa
inhibitor. The patients all received a bolus of andexanet followed by a 2-hour infusion of the
drug. Patients were evaluated for changes in measures of anti–factor Xa activity and were …

Conclusion Andexanet substantially reduces anti-factor Xa activity in patients with acute
major bleeding associated with factor Xa inhibitors. Summary Factor Xa inhibitors are safe
and effective for treatment and prevention of venous thromboembolism and for stroke
prevention in patients with atrial fibulation. However, these agents have been associated
with major and even fatal bleeding events and there has been no reversal agent. Andexanet
alfa is specifically designed to reverse the effects of both direct and indirect factor Xa …