Portola Pharmaceuticals has announced that the FDA designated its investigational Factor Xa inhibitor, andexanet alfa, a breakthrough therapy, according to a press release.
Andexanet alfa is a first-in-class agent intended for patients who experience uncontrolled bleeding or require emergency surgery after treatment with Factor Xa inhibitors. The recombinant, modified Factor Xa molecule binds direct and indirect Factor Xa inhibitors contained in the blood, and reverses the effects of the inhibitors.
The designation follows results from ongoing, phase 2, proof-of-concept studies, in which andexanet alfa immediately reversed the activity of the Factor Xa inhibitors apixaban (Eliquis; Bristol-Myers Squibb, Pfizer) and rivaroxaban (Xarelto, Janssen Pharmaceuticals), with the potential for prolonged reversal with use of an extended infusion. The treatment allows for rapid reinitiation of anticoagulant therapy, and may also reduce incidence of serious adverse events and drug-drug interactions with other therapies, according to the release.
“The FDA’s decision to designate andexanet alfa as a breakthrough therapy reaffirms the urgent need for an antidote to Factor Xa inhibitors, and we believe it demonstrates that andexanet alfa’s properties and data distinguish it from currently used agents or others in development,” William Lis, CEO of Portal Pharmaceuticals, stated in the release. “Procoagulant agents being used in the absence of an antidote are unproven, have limited biological rationale for their effectiveness to reverse Factor Xa inhibitors and have been shown to cause serious blood clots. Therefore, andexanet alfa marks an important advance in the field, and our goal is to bring it to market as quickly as possible.”
The company plans to begin registration-enabling studies during 2014, and is pursuing an Accelerated Approval pathway for the treatment, according to the release.