Artivion (NYSE:AORT) this week stopped the Proact Xa clinical trial that was designed to determine if patients with an On-X mechanical aortic valve can be maintained safely and effectively on apixaban.
The decision to stop the trial was based on the recommendation of the independent Data and Safety Monitoring Board (DSMB). The recommendation cited a lack of evidence supporting non-inferiority of apixaban to warfarin for valve thrombosis and thromboembolism.
Proact Xa was a prospective clinical trial. Patients having an On-X aortic valve replacement randomly received either warfarin or apixaban as their anticoagulant to prevent blood clots. It began enrollment in April 2020.
“The PROACT Xa trial was designed to determine whether apixaban would yield equivalent safety to the standard anticoagulant, warfarin. Unfortunately, it appears that it does not. On behalf of all of the investigators, we appreciate the research effort into the science of managing patients with artificial heart valves,” said Dr. John Alexander, Chair of the PROACT Xa trial and Professor of Medicine/Cardiology at Duke University School of Medicine.
More about the DSMB recommendation
The DSMB found that blood clots occurred more frequently in patients who were receiving apixaban. It determined that continuing the trial was unlikely to achieve the primary endpoint and could expose patients to increased risks. Physicians on the trial are being notified to change patients on apixaban back to warfarin.
“The On-X aortic valve has a long track record of safe and efficacious outcomes and is the leading mechanical aortic valve in the United States and in other markets around the globe. Despite this setback, the On-X aortic valve provides significant clinical benefits to patients and remains the only mechanical aortic valve for which patients can be safely managed with reduced blood thinners, leading to a 60 percent reduction in bleeding,” President and CEO Pat Mackin said.