Key milestones in the development of andexanet alfa as a reversal agent for rivaroxaban and apixaban in adults who experience a major bleeding event. Andexanet alfa acts as a decoy and binds to factor Xa inhibitors, neutralizing the anticoagulant effects of factor Xa inhibitors by preventing the inhibitors from binding to endogenous factor Xa. Intravenous andexanet alfa is a first-in-class recombinant modified factor Xa protein that has been developed by Portola Pharmaceuticals as a universal antidote to reverse the anticoagulant effects of direct or indirect factor Xa inhibitors. warfarin), the risk of bleeding complications still exists and the availability of a specific reversing agent would be beneficial. Although these agents show a better bleeding risk profile compared with that of vitamin K antagonists (e.g. fondaparinux and the low-molecular-weight-heparin enoxaparin) factor Xa inhibitors are effective anticoagulants for the treatment and prevention of thromboembolism, and stroke prevention in atrial fibrillation.

Annexa 4 trial