Andexanet shows promise in patients taking new anticoagulants

Results from an ongoing trial of 228 patients with acute major bleeding show that patients taking andexanet experienced a reduction in anti-FXa activity.

Human blood clotting light micrograph

Factor Xa (FXa) inhibitor reversal agent andexanet rapidly restores haemostasis with an “acceptable” rate of adverse events, in patients taking an FXa inhibitor, a class of anticoagulants including rivaroxaban and apixaban, researchers have found[1]

Speaking at the American College of Cardiology Annual Scientific Session, held in Orlando, Florida, in March 2018, the researchers presented results from their ongoing uncontrolled trial of andexanet, involving 228 patients who presented with acute major bleeding after taking an FXa inhibitor.

The team found that patients receiving an andexanet infusion experienced a median reduction in anti-FXa activity of 92%. At 12 hours, 83% of patients had achieved good or excellent haemostasis. After 30 days, 11% of patients had experienced a thrombotic event and 12% had died.

There are currently no approved reversal agents in the event of potentially fatal, uncontrolled bleeding while taking an FXa inhibitor, therefore some doctors and patients may choose to use other anticoagulants because they have reversal agents.

“Having a safe and effective reversal agent available will benefit patients with acute bleeding,” said lead researcher Stuart Connolly.


[1] Connolly S, Crowther M, Milling T et al. Interim report on the ANNEXA-4 study: andexanet for reversal of anticoagulation in Factor Xa — associated acute major bleeding. Presented at: ACC Annual Scientific Session; 10–12 March 2018; Orlando, Florida. Available at: (accessed May 2018)

Last updated
Clinical Pharmacist, CP, June 2018, Vol 10, No 6;10(6):DOI:10.1211/PJ.2018.20204839

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