Description

• Recombinant Factor Xa inhibitor antidote
• Portola has worldwide rights to develop and commercialize andexanet alfa.

Key Characteristics

• Acts as a Factor Xa decoy that binds and sequesters direct Factor Xa inhibitors in the blood. Once bound to andexanet alfa, the Factor Xa inhibitors are unable to bind to and inhibit native Factor Xa. The native Factor Xa is then available to participate in the coagulation process and restore hemostasis (normal clotting).
• Preclinical and Phase 1 studies suggest that andexanet alfa has the potential to be a universal reversal agent for all Factor Xa inhibitors.

Potential Indications

• Reverse Factor Xa inhibitor anticoagulant activity in patients treated with a Factor Xa inhibitor who suffer an uncontrolled bleeding episode or need to undergo emergency surgery

Clinical Development

Phase 2 proof-of-concept studies are underway or planned. These randomized, double-blind, placebo-controlled studies are designed to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of andexanet alfa after dosing of a direct/indirect Factor Xa inhibitor in healthy volunteers.

• Positive pharmacodynamic and safety data from a Phase 2 study evaluating andexanet alfa with Eliquis® (apixaban) were presented in an oral session at the XXIV Congress of the International Society on Thrombosis and Haemostasis in Amsterdam in July 2013. This study is ongoing to evaluate the administration of andexanet alfa bolus plus extended-duration infusion.
• A Phase 2 study evaluating andexanet alfa and XARELTO® (rivaroxaban) is ongoing.
• Separate studies evaluating andexanet alfa with Lovenox® (enoxaparin), Lixiana® (edoxaban) and betrixaban are planned.