Andexanet alfa (Andexxa, Ondexxya)

概览

Andexanet alfa is a recombinant Factor Xa used to reverse anticoagulation caused by rivaroxaban and apixaban.

作用机制

Factor Xa inhibitors promote anticoagulation by binding to both free Factor Xa in plasma and Factor Xa attached to the prothrombinase complex. This ultimately leads to the blockade of thrombin generation or clot formation . Andexanet alfa is a factor Xa decoy that binds to factor Xa inhibitors such as apixaban and rivaroxaban with high affinity and prevents them from binding to endogenous factor Xa. It was also shown to sequester factor Xa inhibitors, leading to reversing their anticoagulant effects and restoring the activity of endogenous factor Xa . Andexanet alfa may also achieve procoagulation via binding and inhibiting the activity of Tissue Factor Pathway Inhibitor (TFPI), which is an endogenous inhibitor of Factor Xa . Inhibition of TFPI by andexanet alfa resulted in a transient increase in the level of prothrombin fragments 1 and 2, thrombin-antithrombin complex and D-dimer . Subsequently, this may result in increased tissue factor-initiated thrombin generation . Since it is a genetically modified variant of human factor Xa, andexanet alfa is not able to cleave and activate prothrombin nor assemble into the prothrombinase complex .

适应症

Andexanet alfa is indicated for patients treated with rivaroxaban and apixaban, when reversal of anticoagulation is needed due to life-threatening or uncontrolled bleeding . Andexxa has not been shown to be effective for, and is not indicated for, the treatment of bleeding related to any Factor Xa inhibitors other than apixaban and rivaroxaban .

• Severe Life-threatening, uncontrollable Bleeding