Stroke clinical trials at UC Irvine

Researchers are looking for a better way to treat people with atrial fibrillation 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. The way it works, it 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 is, the researchers will compare how often major bleedings occur after taking the study treatments asundexian and apixaban, respectively. Major bleedings are bleedings that have a serious or even life-threatening impact on a person's health. The study participants will be randomly (by chance) assigned to 1 of 2 treatment groups, A and B. Dependent on the treatment group, the participants will either take the study treatment asundexian by mouth once a day or apixaban by mouth twice a day for approximately 9 - 33 months. Each participant will be in the study for approximately 9 - 34 months. There will be visits to the study site every 3 to 6 months and up to 7 phone calls. Those participants who do not want or are unable to have visits to the study site may join the study remotely in selected countries. All visits for these participants will be done using electronic devices. During the study, the study team will: - take blood samples - do physical examinations - examine heart health using an electrocardiogram (ECG) - check vital signs such as blood pressure and heart rate - do pregnancy tests - ask the participants questions about their quality of life - ask the participants questions about how they are feeling and what adverse events they are having. An adverse event is any medical problem that a participant has during a study. Doctors keep track of all adverse events that happen in studies, even if they do not think the adverse events might be related to the study treatments.

Researchers are looking for a better way to prevent an ischemic stroke which occurs when a blood clot travelled to the brain in people who within the last 72 hours had: - a stroke due to a blood clot that formed outside the heart (acute non-cardioembolic ischemic stroke), or - temporary stroke-like symptoms with a high risk of turning into a stroke (high-risk transient ischemic attack), and who are planned to receive standard of care therapy. Ischemic strokes or transient ischemic attacks result from a blocked or reduced blood flow to a part of the brain. They are caused by blood clots that travel to the brain and block the vessels that supply it. If these blood clots form elsewhere than in the heart, the stroke is called non-cardioembolic. People who already had a non-cardioembolic stroke are more likely to have another stroke. This is why they are treated preventively with an antiplatelet therapy, the current standard of care. Antiplatelet medicines prevent platelets, components of blood clotting, from clumping together. Anticoagulants are another type of medicine that prevents blood clots from forming by interfering with a process known as coagulation (or blood clotting). The study treatment asundexian is a new type of anticoagulant currently under development to provide further treatment options. The way it works, it aims to further improve the standard of care with regard to the risk of bleeding. The main purpose of this study is to learn whether asundexian works better than placebo at reducing ischemic strokes in participants who recently had a non-cardioembolic ischemic stroke or temporary stroke-like symptoms when given in addition to standard antiplatelet therapy. A placebo is a treatment that looks like a medicine but does not have any medicine in it. Another aim is to compare the occurrence of major bleeding events during the study between the asundexian and the placebo group. Major bleedings have a serious or even life-threatening impact on a person's health. Dependent on the treatment group, the participants will either take asundexian or placebo as tablets once a day for at least 3 months up to 31 months. Approximately every 3 months during the treatment period, either a phone call or a visit to the study site is scheduled on an alternating basis. In addition, one visit before and up to two visits after the treatment period are planned. During the study, the study team will: - Check vital signs such as blood pressure and heart rate - Examine the participants' heart health using an electrocardiogram (ECG) - Take blood samples - Ask the participants questions about how they are feeling and what adverse events they are having. An adverse event is any medical problem that a participant has during a study. Doctors keep track of all adverse events that happen in studies, even if they do not think the adverse events might be related to the study treatments. In addition, the participants will be asked to complete a questionnaire on quality of life at certain time points during the study.

Objectives - Primary: To test the hypothesis that apixaban is superior to aspirin for the prevention of recurrent stroke in patients with cryptogenic ischemic stroke and atrial cardiopathy. - Secondary: To test the hypothesis that the relative efficacy of apixaban over aspirin increases with the severity of atrial cardiopathy.