SOUTH SAN FRANCISCO, Calif., Nov. 01, 2016 (GLOBE NEWSWIRE) -- Portola Pharmaceuticals Inc. ® (Nasdaq:PTLA) today announced that it has expanded its existing clinical collaboration agreement with Daiichi Sankyo to develop AndexXa™ (andexanet alfa) as an antidote for edoxaban, Daiichi Sankyo's Factor Xa inhibitor. AndexXa is currently under EMA review for reversal of Factor Xa inhibition in patients experiencing a life-threatening or uncontrolled bleed and for patients requiring urgent or emergency surgery. As part of the updated agreement, Portola will expand the ongoing ANNEXA-4 study in bleeding patients in Germany. "As an industry, we need to address the significant unmet medical need for managing Factor Xa inhibitor-related major bleeding by bringing to market an antidote that specifically reverses anti-Factor Xa activity, the anticoagulant mechanism of these agents. With this support from Daiichi Sankyo, we will be able to improve our ability to gather data on AndexXa as a reversal agent for edoxaban. Germany is the second largest market for Factor Xa inhibitors and one where edoxaban has experienced significant growth," said Tao Fu, chief commercial and business officer of Portola. "Our long-standing collaboration with Daiichi Sankyo, as well as all of the other manufacturers of Factor Xa inhibitors, demonstrates the confidence these companies have in the AndexXa program." Under the terms of the non-exclusive agreement with Daiichi Sankyo, Portola will receive a $15 million upfront payment and is eligible to receive up to an additional $10 million upon meeting site initiation and enrollment targets. Upon AndexXa's approval, Daiichi Sankyo will be eligible to receive a low single-digit royalty on AndexXa sales up to a total of $8 million. Portola previously entered into nine separate non-exclusive clinical collaboration agreements with Daiichi Sankyo, BMS, Pfizer, Bayer and Janssen to support Phase 2 and registrational studies of AndexXa in the United States, Europe and Japan. Portola retains all rights, including full commercial and financial rights, for AndexXa outside of Japan.