Portola Pharmaceuticals, a biopharmaceutical company developing innovative drugs that provide significant advances in cardiovascular disease, inflammatory disease and cancer, announced that data related to the Company's series of novel compounds that inhibit spleen tyrosine kinase (Syk) and its novel universal Factor Xa inhibitor antidote will be presented at the annual meeting of the American Society of Hematology (ASH) at the Moscone Center in San Francisco during December 6-9, 2008.

Portola's Syk inhibitor program is focused on developing specific oral inhibitors of this key signaling pathway, which modulate inflammation, certain cancers and thrombosis. The Company plans to study its compounds initially in rheumatoid arthritis and non-Hodgkin's Lymphoma and eventually intends to explore their potential in other inflammatory diseases and cancers.

Portola is developing its universal Factor Xa inhibitor antidote to neutralize the effect of small molecule Factor Xa inhibitors in patients experiencing major bleeding and for patients undergoing emergent or elective surgery.