The FDA has approved the first reversal agent for the commonly prescribed factor Xa inhibitor class of oral anticoagulants. Andexanet alfa (Andexxa®) is a recombinant, inactivated factor Xa protein delivered as an IV bolus in suspected Xa inhibitor-related bleeding events. The drug acts as a “decoy receptor”, binding to the factor Xa inhibitor and freeing endogenous factor Xa to participate in the coagulation cascade.
Millions of patients in the United States take daily factor Xa inhibitor medications, most commonly apixaban (Eliquis®) and rivoraxaban (Xarelto®) and every year several thousands of deaths are attributed to factor Xa inhibitor toxicity. Before andexanet alfa, life-threatening hemorrhage associated with factor Xa inhibition would have been treated with aggressive measures to control site of bleeding and prothrombin complex concentrate infusion.
Andexanet alfa use increases the risk of thromboembolism, cardiac arrest, and sudden death. The most common adverse effects appear to be respiratory infection and urinary tract infection.