Results from a Phase 1 single ascending dose safety and tolerability study of andexanet alfa conducted by Portola in 32 healthy volunteers showed no apparent safety signals, including no thrombotic adverse events and no antibodies against andexanet alfa, endogenous Factor Xa or Factor X. Results from a Phase 2 proof-of-concept study of andexanet alfa were presented at the 2013 Congress of the International Society on Thrombosis and Haemostasis, demonstrating reversal of the anticoagulant activity of Bristol-Myers Squibb’s and Pfizer’s Factor Xa inhibitor Eliquis ® (apixaban).About Portola Pharmaceuticals, Inc. Portola Pharmaceuticals is a biopharmaceutical company focused on the development and commercialization of novel therapeutics in the areas of thrombosis, other hematologic disorders and inflammation. Portola’s wholly-owned lead compound, betrixaban, is a novel, oral, once-daily Factor Xa inhibitor in Phase 3 development for extended-duration prophylaxis of a form of thrombosis known as venous thromboembolism (VTE) in acute medically ill patients. Portola’s second lead development candidate, andexanet alfa (PRT4445), is a recombinant protein in Phase 2 development for which Portola retains full, worldwide commercial rights. It is designed to reverse the anticoagulant activity in patients treated with a Factor Xa inhibitor who suffer an uncontrolled bleeding episode or require emergency surgery. Portola’s third product candidate, PRT2070, is an orally available kinase inhibitor that inhibits both spleen tyrosine kinase (Syk) and janus kinases (JAK). It is targeted at patients with genetically-defined hematologic cancers. Portola’s fourth program, PRT2607 and other highly selective Syk inhibitors, is partnered with Biogen Idec. For more information, visit www.portola.com. Forward-Looking Statements Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding the potential efficacy and use of andexanet alfa to reverse the anticoagulant activity in patients treated with a Factor Xa inhibitor and the timing of the reporting of Phase 2 study data. Risks that contribute to the uncertain nature of the forward-looking statements include the accuracy of Portola’s estimates regarding its ability to complete its clinical studies and the success of Portola’s clinical studies and the demonstrated efficacy of Portola’s product candidates thereunder. These and other risks and uncertainties are described more fully in Portola's filings with the Securities and Exchange Commission, including without limitation its Quarterly Report on Form 10-Q, which was filed with the Securities and Exchange Commission on August 14, 2013. All forward-looking statements contained in this press release speak only as of the date on which they were made. Portola undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.
*PRT4445 has a proposed International Nonproprietary Name (pINN) of andexanet alfa.