Cryolife, Inc. recently received the authorization to begin its PROACT Xa clinical trial as per an Investigational New Drug (IND) application. The randomized trial will help determine if patients with an On-X mechanical aortic valve can be maintained safely on apixaban (Eliquis) rather than warfarin.
On-X Life Technologies is a leading manufacturer of artificial heart valve replacement and repair products. The items are FDA approved and have been successfully implanted in more than 260,000 patients.
Featuring a distinctive design, the On-X Aortic valve is a relatively new heart valve made of a unique material. It’s the only FDA approved mechanical valve that has been proven safe and functions with a significantly less amount of blood thinner (warafin). Furthermore, it has a lower risk of re-operation with the added benefit of lesser bleeding risk.
Patients with mechanical heart valves are prescribed with anticoagulants such as warfarin, and thus require routine blood tests to manage their International Normalized Ratio (INR) within a certain limit – to reduce the likelihood of bleeding and stroke.
INR management can be challenging given the dietary restrictions and drug interactions of a cardiac patient. Despite the drawbacks of a tissue valve, many people, especially younger patients, opt for it to avoid the need to take warafin due to its side effects.
Apixaban can be an alternative for warfarin, giving the patients an incentive to chose On-X Aortic Valve with greater durability and lifetime as compared to the traditional tissue valves.
According to Pat Mackin, Chairman, President, and Chief Executive Officer of CryoLife, “We are pleased that the FDA has authorized us to study the use of apixaban in patients with the On-X Aortic Valve. The On-X Aortic Valve was the first mechanical aortic heart valve to receive both FDA and CE Mark approval for labelling to permit use with a reduced warfarin dosage, based on results of the original PROACT trial which demonstrated a greater than a 60% reduction in bleeding events without increasing the risk of stroke.” Mr. Mackin added, “If the PROACT Xa trial is successful in proving that On-X Aortic Valve recipients can be maintained safely on apixaban rather than warfarin, we believe that not only will we become the leader in the mechanical valve market, but also that the On-X Aortic Valve will take share from the existing bioprosthetic aortic valve market.”
The PROACT Xa is a randomized control trial with around 1000 subjects (500 participants in each arm) over the age of 18 with an On-X Aortic Valve implant, from about 60 sites in North America. Participants will be randomized to either continue warfarin or switch to apixaban.
Each participant will be followed for at least 2 years to determine if apixaban in better than warfarin (INR target range 2.0-3.0) for patients with On-X Aortic Valve for ‘primary composite outcome of valve thrombosis and valve related thromboembolism’, and if it provides acceptable anticoagulation. The primary goal is to evaluate if the alternative is superior in the safety outcome of major bleeding in the patients.
Dr. Alexander talked about the potential alternative for warfarin, saying, “Apixaban has been shown to reduce stroke and cause less bleeding than warfarin in patients with atrial fibrillation. If it can be done safely, the possibility of managing patients with an On-X aortic valve with apixaban and eliminating their need for warfarin represents a potential benefit to patients and the physicians who manage them.”