According to an editorial, moving andexanet from the controlled, sequestered study environment to the real world in the phase 3b–4 study “Prospective, Open-Label Study of Andexanet Alfa in Patients Receiving a Factor Xa Inhibitor Who Have Acute Major Bleeding” may provide critical efficacy and safety information.
The commentator notes that different doses of andexanet used are based on both the type of factor Xa inhibitor ingested and the time from last dose, which has the potential to make its use in the busy emergency department environment challenging; and also raises concerns about underdosing the bleeding patient if clinically obtained information is incorrect. She adds that even if the concentration of anticoagulant in plasma could be measured immediately and the precise required dose of andexanet could be calculated for each anticoagulant, it is unknown whether andexanet would improve outcomes for patients with major bleeding. Additional studies are needed to optimise the use of andexanet and to determine its true efficacy and safety.