Portola Pharmaceuticals Announces AndexXa™ (andexanet alfa), Betrixaban and Cerdulatinib Data to be Presented at 2016 American Society of Hematology Annual Meeting and Exposition

SOUTH SAN FRANCISCO, Calif., Nov. 28, 2016 -- Portola Pharmaceuticals (Nasdaq:PTLA) today announced that clinical and preclinical results from studies of all three of its investigational drugs -- AndexXa™ (andexanet alfa), betrixaban and cerdulatinib -- will be presented at the upcoming 58^th American Society of Hematology (ASH) Annual Meeting and Exposition, which is taking place from December 3-6 at the San Diego Convention Center.

AndexXa, a U.S. Food and Drug Administration (FDA)-designated Breakthrough Therapy, is in development for patients treated with a direct (apixaban, rivaroxaban or edoxaban) or indirect (enoxaparin) Factor Xa inhibitor when reversal of anticoagulation is needed due to life-threatening or uncontrolled bleeding. Betrixaban, which has Fast Track designation from the FDA, is an oral Factor Xa inhibitor anticoagulant in development for the prevention of venous thromboembolism (VTE) in acute medically ill patients. Cerdulatinib, an oral, dual Syk/JAK kinase inhibitor, is in development to treat patients with resistant or relapsed hematologic cancer.

The abstracts are now available at https://ash.confex.com/ash/2016/webprogram/start.html. Following are details of the oral and poster presentations, which will include additional data not available in the abstracts.

AndexXa™ (andexanet alfa)

• Abstract Title: Reversal of betrixaban-induced anticoagulation in healthy volunteers by andexanet alfa

            Publication #: 143
            Presenting Author: Mark Crowther, M.D., MSc, FRCPC, Professor, Department of Medicine, Hematology and Thromboembolism and Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario
            Oral Session Name: 332. Antithrombotic Therapy: Anticoagulation and Bleeding
            Presentation Date and Time: Saturday, December 3, 1:00 p.m. PT
            Presentation Location: Room 30

• Abstract Title: Andexanet alfa reverses anticoagulation effects of enoxaparin and associated bleeding in a rabbit acute hemorrhage model

            Publication #: 1445
            Presenting Author: Pamela B. Conley, Ph.D., Vice President, Biology, Portola Pharmaceuticals
            Poster Session Name: 332. Antithrombotic Therapy: Poster I
            Presentation Date and Time: Saturday, December 3, 5:30-7:30 p.m. PT
            Location: Hall GH

• Abstract Title: Andexanet alfa, a universal antidote under development for Factor Xa inhibitors, reverses rivaroxaban-induced inhibition of thrombin generation initiated by the intrinsic coagulation pathway independent of TFPI

            Publication #: 3831
            Presenting Author: Genmin Lu, Ph.D., Senior Scientist, Portola Pharmaceuticals
            Poster Session Name: 332. Antithrombotic Therapy: Poster III
            Presentation Date and Time: Monday, December 5, 6:00-8:00 p.m. PT
            Location: Hall GH

Betrixaban

• Abstract Title: The safety and efficacy of full versus reduced dose betrixaban in the Acute Medically Ill VTE (venous thromboembolism) Prevention with Extended Duration Betrixaban (APEX) trial

            Publication #: 3824
            Presenting Author: Russell Hull, MBBS, University of Calgary, R.A.H. Faculty of Medicine, Alberta, Canada
            Poster Session Name: 332. Antithrombotic Therapy: Poster III
            Presentation Date and Time: Monday, December 5, 6:00-8:00 p.m. PT
            Location: Hall GH

Cerdulatinib

• Abstract Title: Regulation of B-cell receptor signalling by the tumour microenvironment in chronic lymphocytic leukemia (CLL) and its impact on adhesion and miRNA expression

            Publication #: 351
            Presenting Author: Andrew Steele, Ph.D., Associate Professor, Medicine, University of Southampton, Southampton, UK
            Oral Session Name: 641. CLL: Biology and Pathophysiology, excluding Therapy: CLL Microenvironment: Cell Intrinsic and Extrinsic Factors
            Presentation Date and Time: Sunday, December 4, 10:00 a.m. PT
            Location: Room 5AB

• Abstract Title: Genetic or CD40L-mediated loss of Iκbα is associated with resistance to the dual SYK/JAK inhibitor cerdulatinib in DLBCL cell lines

            Publication #: 2768
            Presenting Author: Greg Coffey, Ph.D., Senior Scientist II, Portola Pharmaceuticals
            Poster Session Name: 605. Molecular Pharmacology, Drug Resistance -- Lymphoid and Other Diseases: Poster II
            Presentation Date and Time: Sunday, December 4, 6:00-8:00 p.m. PT
            Location: Hall GH

About Portola Pharmaceuticals, Inc. 
Portola Pharmaceuticals is a biopharmaceutical company developing product candidates that could significantly advance the fields of thrombosis and other hematologic diseases. The Company is advancing three programs, including betrixaban, an oral, once-daily Factor Xa inhibitor; AndexXa™ (andexanet alfa), a recombinant protein designed to reverse the anticoagulant effect in patients treated with an oral or injectable Factor Xa inhibitor; and cerdulatinib, a Syk/JAK inhibitor in development to treat hematologic cancers. Portola's partnered program is focused on developing selective Syk inhibitors for inflammatory conditions. For more information, visit www.portola.com and follow the Company on Twitter @Portola_Pharma.

Investor Contact:
Ana Kapor		
Portola Pharmaceuticals 
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W2O Group
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