A Study of Andexanet Alfa in Patients Requiring Urgent Surgery or Procedure

Inclusion Criteria: * The patient requires, in the opinion of the Investigator, urgent surgery or procedure and requires reversal of direct oral FXa inhibition. * The patient requires urgent surgery or procedure within 12 hours of informed consent. * The patient requires urgent surgery or procedure that is expected to be associated with a high risk of bleeding or bleeding to occur into a critical organ. * The patient has taken an oral FXa inhibitor (such as apixaban, rivaroxaban, or edoxaban) within 15 hours or more, prior to start of surgery or procedure. * Female patients of childbearing potential must have a negative pregnancy test at Screening. * Willingness to use highly effective methods of contraception (for male and female patients who are fertile). Exclusion Criteria: * The patient requires surgeries or procedures that have a very low chance of causing significant, uncontrollable bleeding, such as small skin procedures, cataract surgery, and minor dental procedures. * The patient has acute life-threatening bleeding at the time of Screening. * The patient will undergo a surgery or procedure which will require the use of heparin. * Patient who is not expected to live for more than three months due to other health problems or has specifically requested not to be resuscitated if their heart stops beating. * Prior to screening, the patient had either experienced low platelet count due to heparin use with or without blood clots or had a genetic condition that affects blood clotting. * Patient has acute decompensated heart failure, cardiogenic shock, sepsis, or septic shock at the time of Screening. * Patient has history of heparin-induced thrombocytopenia (with or without thrombosis) or inherited coagulopathy (eg, anti-thrombin III deficiency, anti-phospholipid antibody syndrome, protein C/S deficiency, Factor V Leiden) at the time of Screening. * Previously diagnosed with a bleeding disorder (eg, platelet function disorder, hemophilia, Von Willebrand disease, or coagulation factor deficiency). * Prior known hypersensitivity to andexanet alfa. * Use of andexanet alfa 30 days prior to Screening. * Patient diagnosed with dementia. * Any prohibited medication as determined in the study.