Andexanet alfa: Phase III data

Top-line data from 33 healthy volunteers ages 50-75 in part 1 of the 2-part, double-blind, U.S. Phase III ANNEXA-A trial showed that a 400 mg IV bolus of andexanet alfa met the primary endpoint of reversing the anticoagulant activity of Eliquis apixaban as measured by the mean change in anti-Factor Xa levels from baseline at 2 or 5 minutes after the end of the bolus vs. placebo. Portola also said andexanet alfa met secondary endpoints of change in unbound Eliquis plasma levels and thrombin generation. Andexanet alfa was well tolerated with no serious adverse events reported. Patients received twice-daily 5 mg Eliquis for 4 days followed by placebo or andexanet alfa on day 4 given 3 hours after the last Eliquis dose. Data will be presented at the American Heart Association meeting in Chicago in November.

Part 2 of the trial will enroll 32 healthy volunteers ages 50-75 to receive twice-daily 5 mg Eliquis for 4 days followed by placebo or andexanet alfa administered as a 400 mg IV bolus followed by a continuous infusion of 480 mg andexanet alfa at 4 mg/minute for 120 minutes. Data from part 2 are expected in early 2015. At the end of 2015, Portola plans to submit a BLA to FDA seeking accelerated approval of andexanet alfa to reverse the anticoagulant activity of Factor Xa inhibitors. ...