Anticoagulant medications, or blood thinners, are often used to help prevent blood clots. This is important for people with an irregular heartbeat known as atrial fibrillation (AFib), as they are five times more likely to have a stroke due to blood clots.
UAB St. Vincent’s is conducting an international clinical trial for a new anticoagulant medication for people with AFib to reduce the risk of blood clots. This new medication, called Factor XI, is being tested in those who cannot otherwise take blood thinners due to the risk of bleeding.
The clinical trial began enrolling patients in fall 2023 and will be following them over the course of the five-year study. More than 2,000 people have been enrolled in Asia, Europe, and Central and North America, with the goal of 15,000 over the entire course of the trial. UAB St. Vincent’s is one of only two hospitals in Alabama conducting the trial.
“These medications work by inhibiting the clotting process and reducing the ability of the blood to form clots,” said Alain Bouchard, M.D., cardiologist and principal investigator for the UAB St. Vincent’s clinical trial. “In our blood, we have proteins that are called coagulation factor. If you cut yourself, it’s important to have a mechanism to stop the bleeding. The coagulation factor is very important just for that.”
Better medications needed
AFib causes an irregular heartbeat, so the ventricles in the heart may not be pumping blood between the heart’s chambers well enough. This can lead to a pooling of the blood, making clots more likely to form. There are medications available to prevent stroke, but they can cause excessive bleeding.
“We need better medications that not only will prevent a stroke but also will not cause this bleeding,” Dr. Bouchard said.
The trial at St. Vincent’s involves drugs called Factor XI inhibitors. Dr. Bouchard says there are 12 coagulation factors in the human body that normally help stop bleeding. For people at a high risk of stroke, blood clotting factors need to be blocked to prevent too much clotting. Some medications block certain factors that can lead to increased bleeding.
Finding a balance
Dr. Bouchard says a Factor XI inhibitor may be the key to finding the balance between too much clotting and not enough.
“Factor XI is there as a bystander if you cut yourself, but it is very essential to forming clots,” Dr. Bouchard said. “Studies so far have shown that using Factor XI can reduce the complication of a blood clot without causing an increased risk of bleeding.”
UAB St. Vincent’s is testing two different types of medication during this trial. One is an injectable version of Factor XI designed for people who are at higher risk for bleeding and have been unable to take any form of blood thinner. The second study focuses on the pill form, which is similar to apixaban (Eliquis).
“This is a really exciting time in medicine, and we are very fortunate to offer these options to patients,” Dr. Bouchard said. “The future for patients with AFib is very bright.”
To learn more, please contact the UAB St. Vincent’s Research Department at 205-212-6031.