Portola's mitigating factors

An underpowered cohort appears to be the culprit behind the Phase III miss for betrixaban, but Portola Pharmaceuticals Inc. plans to pursue an NDA submission for the oral Factor Xa inhibitor based on the totality of the evidence, including an unexpected finding of fewer major bleeds.

Data reported by Portola on March 24 showed betrixaban failed to show superiority to enoxaparin in the 7,513-patient Phase III APEX trial to prevent venous thromboembolism (VTE) in acute medically ill patients hospitalized with heart failure, respiratory failure, infection, rheumatic disease or stroke, and who were severely immobilized for 24 hours during hospitalization and moderately or severely immobilized for at least four days after hospital admission...