Portola Pharmaceuticals announced that the Center for Biologics Evaluation and Research (CBER) of the U.S. Food and Drug Administration (FDA) has accepted the Biologics License Application (BLA) for andexanet alfa for filing under a priority review. Portola submitted the BLA in December 2015 under an Accelerated Approval pathway. The FDA is expected to take action on the application by the Prescription Drug User Fee Act (PDUFA) action date of August 17, 2016.
Andexanet alfa, an FDA-designated breakthrough therapy, is specifically designed to reverse the anticoagulant activity of both direct and indirect Factor Xa inhibitors. Portola is developing the antidote for patients treated with a direct or indirect Factor Xa inhibitor when reversal of anticoagulation is needed, such as in life-threatening or uncontrolled bleeding or for emergency surgery and urgent procedures.
The andexanet alfa BLA is based on data from preclinical, Phase 1 and 2, manufacturing and Phase 3 studies. The Phase 3 ANNEXA™ (Andexanet Alfa a Novel Antidote to the Anticoagulant Effects of FXa Inhibitors) studies evaluated the safety and efficacy of andexanet alfa in reversing the anticoagulant activity of the Factor Xa inhibitors rivaroxaban and apixaban in healthy volunteers. Results of those studies were published by The New England Journal of Medicine in November 2015. The BLA also included limited adjudicated efficacy and safety data from initial patients enrolled in the ongoing Phase 4 ANNEXA-4 study. Portola is currently evaluating andexanet alfa in this global, single-arm, open-label confirmatory study in patients receiving apixaban, rivaroxaban, edoxaban or enoxaparin (a low molecular weight heparin and indirect Factor Xa inhibitor) who present to the hospital with an acute major bleed.
