Portola Pharmaceuticals, Inc. Announces Upcoming Oral Presentation of Data on PRT4445, a First-in-Class Universal Factor Xa Inhibitor Antidote, at European Society of Cardiology 2012 Congress

SOUTH SAN FRANCISCO, CA--(Marketwire - August 23, 2012) - Portola Pharmaceuticals, Inc. today announced that data from a preclinical study of PRT4445, the first universal Factor Xa inhibitor antidote in clinical development, will be presented in an oral session at the upcoming European Society of Cardiology (ESC) Congress 2012 in Munich.

PRT4445 is a recombinant biologic designed to reverse the anticoagulant activity of oral and injectable Factor Xa inhibitors in patients suffering life-threatening bleeds or requiring urgent surgery. It is being evaluated in a Phase 1 single ascending dose safety and tolerability study in healthy volunteers. PRT4445 is a companion product to betrixaban, a novel, oral, once-daily Factor Xa inhibitor. Portola is evaluating betrixaban in its global, pivotal Phase 3 APEX Study to show superiority to the current standard of care for hospital and post-discharge prevention of venous thromboembolism (VTE) in acute medically ill patients, a multi-billion dollar indication for which there are no approved therapies for use post hospital discharge.

Details of the oral presentation follow:

Abstract title: Recombinant factor Xa inhibitor antidote (PRT064445) mediates reversal of anticoagulation through reduction of free drug concentration: a common mechanism for direct factor Xa inhibitors
Session: Safety of antithrombotic drugs: from bench to practice
Presentation date/time: Monday, August 27, 3:00 p.m. local time
Presenter: Uma Sinha, Ph.D., Vice President, Head of Biology, Portola Pharmaceuticals
Location: Budapest - Village 4, Internationales Congress Center München, Messe München
Final Program #: 2962

About Portola Pharmaceuticals, Inc.
Portola Pharmaceuticals discovers and develops innovative therapeutics based on targets with established proof of concept that are designed to provide significant advances over current treatments for cardiovascular and autoimmune/inflammatory diseases. Portola scientists have successfully collaborated for over 15 years on the discovery and development of novel small molecule agents targeting platelets, coagulation pathways and protein kinases. In thrombosis, Portola is independently developing betrixaban and PRT4445. In inflammation, Portola is collaborating with Biogen Idec to develop and commercialize highly selective, novel oral Syk inhibitors for the treatment of various autoimmune and inflammatory diseases, including rheumatoid arthritis and systemic lupus erythematosus. The collaboration’s lead molecule, PRT2607, has been shown to be a highly potent and specific oral inhibitor of Syk. Portola’s broad chemistry capability also has led to the discovery of dual inhibitors of Syk and Janus Kinase (JAK) for chronic autoimmune indications and oncology. For additional information, visit www.portola.com.