Asundexian was associated with a higher incidence of stroke or systemic embolism, but less major bleeding, compared with apixaban among patients with atrial fibrillation (AFib) who were at high risk for stroke, based on findings from the OCEANIC-AF trial presented at ESC Congress 2024 in London and simultaneously published in The New England Journal of Medicine. However, researchers noted that the trial was stopped prematurely and more research is necessary.

OCEANIC-AF researchers randomized 14,810 patients to receive either 50 mg once daily of asundexian, an activated XI (Xia) inhibitor, or a standard dose of apixaban. Of the participants, 35.2% were women, 18.6% had chronic kidney disease, 18.2% had a previous stroke or transient ischemic attack, 16.8% had received oral anticoagulants for no more than six weeks, and the mean CHA2DS2-VASc score was 4.3±1.3.

Prior to the trial being stopped early at the recommendation of the independent data monitoring committee, stroke or systemic embolism occurred in 98 patients (1.3%) receiving asundexian and in 26 (0.4%) receiving apixaban. Major bleeding occurred in 17 patients (0.2%) in the asundexian group and in 53 (0.7%) in the apixaban group. The incidence of any adverse event was similar in the two groups.

"We conducted the phase III OCEANIC-AF trial to test whether asundexian could prevent stroke and systemic embolism to the same extent as apixaban; however, asundexian was found to be inferior," said Principal Investigator Manesh Patel, MD, FACC.

Looking ahead, the OCEANIC-AF investigators note that "more research is needed to determine whether the concept of factor XIa inhibition may become an option for stroke prevention in patients with AFib and, if so, in which population and what degree of factor XIa inhibition is necessary to effectively and safely achieve this." They add that findings from several studies currently underway should help provide clarity.