BayerBayer today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation for its investigational drug asundexian (BAY2433334) as a potential treatment to prevent stroke and systemic embolism in people with atrial fibrillation (AF). This news follows asundexian's first U.S. FDA Fast Track Designation for the prevention of stroke in patients after a non-cardioembolic ischemic stroke, which was granted in 2022.

Asundexian is an investigational agent and has not been approved by any health authority for use in any country, for any indication. It is currently being evaluated as a potential once-daily oral Factor XIa (FXIa) inhibitor in thrombosis prevention with the goal to reduce clot formation while leaving the body’s ability to respond to bleeding intact.

Fast Track Designation is intended to facilitate the development and expedite the review of drug candidates to treat serious medical conditions and fulfill unmet medical needs. The purpose of the program is to get important new therapeutics to the patient earlier. A drug candidate that receives Fast Track Designation may be eligible for more frequent interactions with the U.S. FDA to discuss the drug candidate’s development plan and, if relevant criteria are met, eligibility for Accelerated Approval and Priority Review.

"The second Fast Track Designation for asundexian emphasizes the medical need to prevent stroke and systemic embolism in people diagnosed with atrial fibrillation," said Christian Rommel, Member of the Executive Committee of Bayer AG's Pharmaceutical Division and Head of Research and Development. "This designation provides an opportunity to accelerate the development of asundexian and quickly address current patient needs. Despite significant advances in treatment, potential concerns of bleeding risks remain at the forefront of thrombosis management. Asundexian is currently investigated as a candidate in an entirely new class of antithrombotic treatment options aiming to selectively modulate coagulation, address patients with concerns of bleeding, and focus on indications where current anticoagulation is not used."

It is estimated that up to 40% of eligible patients are either not treated with direct oral anticoagulants or are undertreated, as patients perceive the risk of experiencing bleeding outweigh their need for thrombosis prevention.(1) Inhibition of FXIa by asundexian could provide protection from thrombotic events without a corresponding increase in bleeding risk.

About the OCEANIC Program

The OCEANIC clinical trial program is designed to evaluate the use of oral FXIa inhibitor, asundexian, in patients with atrial fibrillation (AF) at risk of stroke and in patients with acute non-cardioembolic ischemic stroke or high-risk transient ischemic attack (TIA), aiming to improve the benefit-risk profile when compared to current treatment options. The program started with two large multinational studies, OCEANIC-AF and OCEANIC-STROKE, and is one of the largest Phase III programs Bayer has undertaken, expecting to enroll more than 27,000 patients in over 40 countries.


OCEANIC-AF is a multicenter, international, randomized, active comparator-controlled, double-blind, double-dummy, parallel-group, two-arm Phase III study investigating asundexian compared to apixaban (a non-vitamin K antagonist oral anticoagulant) in patients with atrial fibrillation at risk for stroke to determine the safety and efficacy of asundexian on prevention of stroke and systemic embolism.

OCEANIC-STROKE is a multicenter, international, randomized, placebo-controlled, double-blind, parallel group and event-driven Phase III study investigating the efficacy and safety of asundexian for prevention of ischemic stroke compared to placebo on top of standard-of-care antiplatelet therapy in patients after a non-cardioembolic ischemic stroke or high-risk TIA.

About FXIa inhibitors and Asundexian

Factor XI is a protein in the blood which is converted into its active enzyme form (Factor XIa) as part of the blood coagulation cascade. FXIa inhibition specifically targets the FXIa protein involved in pathological thrombus formation, but leaves the pathway involved in the physiological healing of vessel wall injuries intact. Asundexian, as an oral direct, potent inhibitor of activated coagulation factor XI (FXIa), acts selectively on the coagulation cascade, thereby offering the potential to prevent events like stroke without a corresponding increase in bleeding risk. Asundexian is currently being evaluated as a potential improved treatment option in thrombosis prevention and could represent a new approach in antithrombotic treatment. Asundexian is a once-daily, oral investigational agent and has not been approved by any health authority for use in any country, for any indication.

About Atrial Fibrillation

AF is one of the most common sustained cardiac rhythm disorders (arrhythmias). It results from rapid, disorganized electrical signals in the upper chambers (atria) of the heart, causing them to quiver and contract quickly and irregularly. As a result, the atria do not empty completely, and blood does not flow properly, causing blood clots to form. These blood clots can break loose and travel to the brain, resulting in a stroke.(2)

About Bayer

Bayer is a global enterprise with core competencies in the life science fields of health care and nutrition. Its products and services are designed to help people and the planet thrive by supporting efforts to master the major challenges presented by a growing and aging global population. Bayer is committed to driving sustainable development and generating a positive impact with its businesses. At the same time, the Group aims to increase its earning power and create value through innovation and growth. The Bayer brand stands for trust, reliability and quality throughout the world. In fiscal 2022, the Group employed around 101,000 people and had sales of 50.7 billion euros. R&D expenses before special items amounted to 6.2 billion euros.

1. E, Wolff A, Lip GY, Lane DA. Optimising stroke prevention in patients with atrial fibrillation: application of the GRASP-AF audit tool in a UK general practice cohort. Br J Gen Pract. 2015 Jan;65(630):e16-23. doi: 10.3399/bjgp15X683113. PMID: 25548312; PMCID: PMC4276003.​
2. NHS choices. Atrial fibrillation complications. Available at: Accessed: May 2023