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Study on Asundexian and Apixaban for Preventing Stroke in Adults with Atrial Fibrillation at Risk for Stroke

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the prevention of stroke or systemic embolism in people with atrial fibrillation, a condition where the heart beats irregularly and often rapidly. The study is comparing two treatments: asundexian (also known by its code name BAY 2433334) and apixaban, which is marketed under the name Eliquis. Both medications are taken orally in the form of film-coated tablets. The purpose of the study is to determine how well asundexian works and how safe it is compared to apixaban in preventing stroke or systemic embolism in individuals with atrial fibrillation who are at risk for stroke.

Participants in the study will be randomly assigned to receive either asundexian or apixaban. Some participants will receive a placebo, which is a substance with no active medication, to help compare the effects of the treatments. The study will be conducted in a double-blind manner, meaning neither the participants nor the researchers will know who is receiving which treatment, to ensure unbiased results. The trial will last for a period of up to 33 days, during which the safety and effectiveness of the treatments will be closely monitored.

The main goal is to see if asundexian is at least as effective as apixaban in preventing stroke and systemic embolism, and to assess the risk of major bleeding, which is a significant concern with blood-thinning medications. The study will also look at other outcomes, such as the occurrence of minor bleeding, cardiovascular events, and overall mortality. This research aims to provide valuable information on the potential benefits and risks of asundexian compared to apixaban for people with atrial fibrillation at risk of stroke.

The research process

The trial runs in 2 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Participation in the study

    After joining the study, one of two treatment paths is assigned. the assignment is random, meaning it is decided by chance, and is double-blind, which means neither the participant nor the doctors know which specific medication is being taken.

    The study uses a double-dummy method. this means two different types of pills are taken to ensure that every participant takes the same number of tablets, even if one is an active medicine and the other is a placebo (a pill with no active medicine).

  2. Step 2

    Medication administration

    One group receives asundexian (50 mg) in a tablet form taken by mouth, along with a placebo tablet that looks like the apixaban medication.

    The other group receives apixaban (either 5 mg or 2.5 mg) in a tablet form taken by mouth, along with a placebo tablet that looks like the asundexian medication.

    The specific dose of apixaban is determined by the medical requirements for the prevention of stroke (a sudden interruption of blood flow to the brain) or systemic embolism (when a blood clot travels through the bloodstream to another part of the body) in individuals with atrial fibrillation (an irregular and often rapid heartbeat).

Who can join the trial?

7 criteria

  • You must be 18 years of age or older at the time you sign the agreement to join the study.
  • You must have atrial fibrillation, which is an irregular and often rapid heart rhythm that can cause blood to pool in the heart.
  • Your heart rhythm must be confirmed by an ECG, which is a test that records the electrical activity of your heart.
  • You must require long-term treatment with an oral anticoagulant, which is a type of medicine taken by mouth that helps prevent blood clots from forming.
  • You must have a specific risk score, known as a CHA2DS2-VASc score, which is a tool doctors use to estimate the likelihood of having a stroke based on certain health factors.
  • For men, this score must be 3 or higher, or 2 if certain other specific study requirements are met.
  • For women, this score must be 4 or higher, or 3 if certain other specific study requirements are met.

Who cannot join the trial?

4 criteria

  • Having a mechanical heart valve prosthesis, which is an artificial valve surgically placed in the heart to replace a damaged natural valve.
  • Having moderate-to-severe mitral stenosis, a condition where the mitral valve (one of the heart's valves) becomes narrow and stiff, making it difficult for blood to flow through the heart.
  • Having atrial fibrillation—an irregular and often rapid heart rhythm—that is caused only by a reversible cause, meaning a condition that can be easily fixed or cured.
  • Needing chronic anticoagulation, which is long-term medication used to thin the blood and prevent clots, for any reason other than atrial fibrillation.
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Investigated drugs

  • Asundexian

    is a medication being tested to see how well it prevents blood clots that could lead to a stroke or other serious issues in people with an irregular heartbeat called atrial fibrillation. It works by blocking a specific protein in the blood that helps clots form.

  • Apixaban

    is an existing medication used to prevent blood clots, such as those that cause strokes or systemic embolism, in people with atrial fibrillation. In this study, it is used as a comparison to see how effective it is against the new medication.

What is already known about the treatment

  • Apixaban

    This medication is taken by mouth in the form of film-coated tablets and is currently widely used in medical practice. It is primarily prescribed to prevent blood clots, strokes, or systemic blockages in patients with irregular heartbeats known as atrial fibrillation. As a blood thinner belonging to a group called direct oral anticoagulants, it works by specifically blocking a protein in the blood called Factor Xa, which helps stop the formation of dangerous clots.

  • Asundexian

    This substance is administered orally as a film-coated tablet and is currently being studied in clinical trials for its medical potential. It is intended to help prevent strokes or blood clots in people with atrial fibrillation by targeting the blood clotting process. Classified as a Factor XI inhibitor, it works at the molecular level by blocking a specific protein called Factor XI, which helps reduce the risk of clots while potentially lowering the chance of bleeding.

Investigated diseases

  • Atrial fibrillation

    This is an irregular and often rapid heart rhythm that can cause many different symptoms. It occurs when the upper chambers of the heart beat out of sync with the lower chambers. During this condition, the heart's electrical signals become disorganized. This irregular beating can cause blood to pool in the heart. Over time, this pooling can lead to the formation of blood clots. These clots may then travel through the bloodstream to other parts of the body.

  • Stroke

    A stroke occurs when the blood supply to part of the brain is interrupted or reduced. This interruption prevents brain tissue from getting necessary oxygen and nutrients. Brain cells can begin to die within minutes due to this lack of blood flow. This condition can also be caused by a blood vessel in the brain bursting. The damage to the brain can affect various bodily functions depending on the location.

  • Systemic embolism

    This condition happens when a blood clot or other foreign object travels through the bloodstream. The object moves from its original location and becomes stuck in a blood vessel in a different part of the body. This blockage can restrict blood flow to vital organs or limbs. The location of the blockage determines which part of the body is affected. It is often a result of a clot forming in the heart or large arteries.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-503794-38-00Protocol code19767Estimated enrolment17 460 patientsSponsorBayer AG

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