Andexanet Alfa effectively controls acute major bleeding due to Factor Xa Inhibitors

A recent study published in the Circulation Journal found andexanet alfa effective in reversing the effects of Factor Xa Inhibitors and achieving hemostasis in patients with acute major bleeding.

Andexanet alfa is a modified recombinant inactive factor Xa (FXa) designed to reverse Factor Xa Inhibitors. A phase-3b/4, multicenter, prospective, single-group cohort study (ANNEXA-4) by Truman Milling Jr and peers carefully evaluated the efficacy and safety of andexanet alfa in patients with acute major bleeding within 18 hours of FXa inhibitor administration.

The study included 479 patients with bleeding predominantly in the intracranial or gastrointestinal areas. The co-primary endpoints were anti-FXa activity change from baseline during andexanet alfa treatment and excellent or good hemostatic efficacy at 12 hours. The efficacy population included patients with baseline anti-FXa activity levels above predefined thresholds who met the major bleeding criteria, and the safety population included all patients.

The key highlights of the study were:

Andexanet alfa reduced anti-FXa activity in patients treated with apixaban, rivaroxaban, edoxaban, and enoxaparin by 93%, 94%, 71%, and 75%, respectively.

Excellent or good hemostasis occurred in 80% of patients with major bleeding.

Thrombotic events occurred in 10% of patients in the safety population, with no thrombotic episodes occurring after oral anticoagulation restart. Median endogenous thrombin potential was within the normal range by the end of andexanet alfa bolus through 24 hours for all FXa inhibitors.

The study supports the use of andexanet alfa as a safe and effective antidote for FXa inhibitors in patients with acute major bleeding.

Source:

Milling, T. J., Jr, Middeldorp, S., Xu, L., Koch, B., Demchuk, A., Eikelboom, J. W., Verhamme, P., Cohen, A. T., Beyer-Westendorf, J., Michael Gibson, C., Lopez-Sendon, J., Crowther, M., Shoamanesh, A., Coppens, M., Schmidt, J., Albaladejo, P., Connolly, S. J., Anand, R., Bastani, A., … Demchuk, A. M. (2023). Final Study Report of Andexanet Alfa for Major Bleeding With Factor Xa Inhibitors. In Circulation. Ovid Technologies (Wolters Kluwer Health). https://doi.org/10.1161/circulationaha.121.057844.