Company Expects to Report Top-Line Results at End of First Quarter 2016–
Betrixaban Has Potential to Become First Oral Factor Xa Inhibitor Anticoagulant
Approved for Prevention of VTE in Acute Medically Ill–

SOUTH SAN FRANCISCO, CA, USA I October 30, 2015 I Portola Pharmaceuticals (PTLA) today announced it has completed patient enrollment in the pivotal Phase 3 APEX (Acute Medically Ill VTE Prevention with Extended Duration Betrixaban) Study. The 7,500-patient study is evaluating betrixaban, an investigational oral, once-daily Factor Xa inhibitor anticoagulant, for extended-duration prevention of venous thromboembolism (VTE), or blood clots, in acute medically ill patients. These are patients who are hospitalized for serious medical conditions, such as heart failure, stroke, infection and pulmonary disease.

Portola plans to report top-line data at the end of the first quarter of 2016. If the trial is successful, the Company expects to submit a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) in the second half of 2016 under Fast Track designation.

“Enrolling patients in the APEX Study was a significant accomplishment for Portola, the academic leadership of the study, and the more than 450 trial sites worldwide that enrolled patients.  We would like to thank all of the patients who participated in this groundbreaking study,” said John T. Curnutte, M.D., Ph.D., executive vice president, research and development, for Portola. “If APEX is successful, betrixaban will advance the field of thrombosis by being the first anticoagulant to address the significant unmet medical need for preventing VTE in acute medically ill patients in both the hospital and home settings.  Moreover, APEX is the first study to use a biomarker, D-dimer, in this setting to identify patients most likely to benefit from anticoagulation therapy.”

An estimated 20 million acute medically ill patients in the G7 countries are at risk of developing VTE — which includes both deep vein thrombosis (DVT), a blood clot in the leg, and pulmonary embolism (PE), a clot that breaks loose and travels to the lungs — either while in the hospital or following discharge. More than 1 million VTEs and 150,000 VTE-related deaths occur in acute medically ill patients each year in the G7 countries, despite the use of injectable enoxaparin in the hospital. Although more than half of VTE events occur after the patient is discharged from the hospital, no anticoagulant, including any of the marketed oral Factor Xa inhibitors, is approved for use in both the hospital setting and for the extended post-discharge period. 

About the APEX Study

The Phase 3 APEX Study is evaluating the superiority of extended-duration anticoagulation with oral betrixaban (for 35-42 days) compared with standard of care anticoagulation with injectable enoxaparin (for up to 14 days) for the prevention of VTE in acute medically ill patients. APEX  enrolled 7,500 patients at 450 clinical sites worldwide. The study used a biomarker-based design to identify and enroll patients at highest risk of VTE and most likely to benefit from betrixaban – specifically, those with an elevated level of D-dimer (a protein fragment present after a blood clot has developed) and those over age 75.

About Betrixaban

Betrixaban directly inhibits the activity of Factor Xa, an important validated target in the blood coagulation pathway, to prevent life-threatening thrombosis. Betrixaban has distinct properties that may allow it to demonstrate clinical benefit without the significant imbalance in the risk of fatal bleeding seen with other agents in the class. These include a 19-25-hour half-life for once-daily dosing; a low peak-to-trough drug concentration ratio that minimizes anticoagulant variability; low renal clearance; and no significant CYP3A4 metabolism, which may reduce the risk of drug-drug interactions.

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 its three wholly-owned programs using novel biomarker and genetic approaches that may increase the likelihood of clinical, regulatory and commercial success of its potentially life-saving therapies. These programs include betrixaban, an oral, once-daily Factor Xa inhibitor being evaluated in the APEX Phase 3 study for prophylaxis of venous thromboembolism (VTE); 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.

SOURCE: Portola Pharmaceuticals