Artivion has halted the PROACT Xa clinical trial, which was designed to assess if patients with an On-X mechanical aortic valve could be maintained safely and effectively on apixaban versus warfarin.
The randomised, prospective trial enrolled subjects with an On-X aortic valve replacement to receive either warfarin or apixaban as the anticoagulant for preventing blood clots.
In April 2020, the trial commenced subject enrolment.
The latest move comes after the independent Data and Safety Monitoring Board (DSMB) recommended stopping the trial due to a lack of evidence for apixaban’s non-inferiority compared to warfarin in cases of valve thrombosis and thromboembolism.
The board also found that blood clots, which lead to stroke, were reported more regularly in subjects who were given apixaban.
According to the DSMB, it was unlikely that the primary endpoint would be met if the trial continued to progress, and it could potentially expose trial subjects to greater risk.
Physician investigators at the study sites are being notified of the development and instructed to move the subjects receiving apixaban to the warfarin arm.
Artivion chairman, president and CEO Pat Mackin said: “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% reduction in bleeding.
“We are disappointed to stop the PROACT Xa trial, as a successful trial would have significantly benefited patients and significantly increased our addressable market opportunity beginning in 2025.”