Portola Reports Topline Results From Second Part Of Phase 3 ANNEXA-A Study

(RTTNews) - Portola Pharmaceuticals (PTLA) announced positive topline results from the second part of the Phase 3 ANNEXA-A study, which evaluated the safety and efficacy of andexanet alfa, an investigational antidote, with the Factor Xa inhibitor Eliquis (apixaban) in healthy volunteers.

Andexanet alfa was administered as an intravenous bolus followed by a continuous two-hour infusion to sustain the reversal of anticoagulation activity. The company reported that the study achieved all primary and secondary endpoints with high statistical significance. Andexanet alfa produced rapid reversal of the anticoagulant effect of apixaban, as measured by anti-Factor Xa activity, which was sustained for the duration of the infusion.

In the study, andexanet alfa was well tolerated, with no serious adverse events, thrombotic events, or antibodies to Factor X or Xa reported, the company said.

Portola plans to submit data from the ANNEXA-A and ANNEXA-R studies, and initial data from a Phase 4 study, as part of its Biologics License Application to the FDA under an Accelerated Approval pathway by the end of 2015.