Portola Pharmaceuticals has entered into a second clinical collaboration agreement with Bristol-Myers Squibb and Pfizer to study Portola's investigational Factor Xa inhibitor reversal agent, andexanet alfa (PRT4445), with the oral Factor Xa inhibitor Eliquis (apixaban). The original agreement from November 2012 covered the Phase II proof-of-concept study and results demonstrated andexanet alfa's ability to produce an immediate and either temporary or sustained reversal of the anticoagulation activity of Eliquis. The new clinical agreement includes Phase III studies with Eliquis and any potential U.S. and EU regulatory approval of andexanet alfa.
Portola will receive an upfront payment and is eligible to receive additional development and regulatory milestones. BMS and Pfizer will continue to provide development and regulatory guidance for the program. Portola retains full, worldwide commercial rights to andexanet alfa, which was designated as a breakthrough therapy by the FDA in November 2013.
"We are pleased to continue our collaboration with Bristol-Myers Squibb and Pfizer, which has been instrumental in accelerating andexanet alfa's development as a potential agent to reverse the anticoagulation effect of Eliquis," said William Lis, chief executive officer of Portola. "The FDA's recent designation of andexanet alfa as a breakthrough therapy recognizes the medical need for this antidote as well as its attributes, which distinguish it from general procoagulant approaches. Andexanet alfa is the only agent that has been shown to reverse the anticoagulation effect of Factor Xa inhibitors in humans."