A Study to Learn How Well the Study Treatment Asundexian Works and How Safe it is Compared to Apixaban to Prevent Stroke or Systemic Embolism in People With Irregular and Often Rapid Heartbeat (Atrial Fibrillation), and at Risk for Stroke

Study Summary

Researchers are looking for a better way to treat people with atrial fibrillation (AF) and prevent stroke or systemic embolism (blood clots travelling through the blood stream to plug another vessel). Atrial fibrillation is a condition of having irregular and often rapid heartbeat. It can lead to the formation of blood clots in the heart which can travel through the blood stream to plug another vessel, and like this lead to serious and life-threatening conditions, such as a stroke. A stroke occurs because the brain tissue beyond the blockage no longer receives nutrients and oxygen so that brain cells die. As strokes arising from atrial fibrillation can involve extensive areas of the brain, it is important to prevent them. Blood clots are formed in a process known as coagulation. Medications are already available to prevent the formation of blood clots. When taken by mouth (orally), they are known as oral anticoagulants (OACs) including apixaban. OACs decrease the risk of the above-mentioned serious and life-threatening conditions. The main side effect of OACs is an increase of the risk of bleeding. The study treatment asundexian is a new type of anticoagulant currently under development to provide further treatment options. Asundexian aims to further improve the standard of care with regard to the risk of bleeding. The main purpose of this study is to collect more data about how well asundexian works to prevent stroke and systemic embolism and how safe it is compared to apixaban in people with atrial fibrillation and at high risk for stroke. To see how well the study treatment asundexian works researchers compare: * how long asundexian works well and * how long apixaban works well after the start of the treatment. Working well means that the treatments can prevent the following from happening: * stroke and/or * systemic embolism. The study will keep collecting data until a certain number of strokes or embolisms happen in the study. To see how safe asundexian

Primary Outcome

The assessment was based on the cause-specific hazard ratio (csHR), comparing asundexian with apixaban which is based on time to first event. Stroke was defined as an acute episode of focal or global neurological dysfunction caused by an injury of the brain, spinal cord, or retina as a result of hemorrhage or infarction. Systemic embolism is defined as abrupt vascular insufficiency associated with clinical or radiological evidence of arterial occlusion in the absence of other likely mechanisms

Interventions

• DRUG Apixaban
• DRUG Asundexian (BAY2433334)
• DRUG Asundexian matching placebo
• DRUG Apixaban matching placebo