Hemophilia A; Hemophilia B

Inclusion Criteria

- Males with severe congenital hemophilia A or B defined as <1% FVIII or <2% FIX concentration by measurement at the time of screening or from reliable prior documentation (e.g., measurement in other clinical Bayer trials, or diagnostic genetic testing)
- Male with any inhibitor titer at screening or prior to screening at any time from medical records. Subjects may be receiving a bypassing agent (rFVIIa; NovoSeven and/or aPCC; FEIBA) for treatment.
- Age: 18 to 65 years at screening
- BMI: 18 to 29.9 kg/m2

Exclusion Criteria

- Subjects with known bleeding disorders (such as von Willebrand factor [vWF] deficiency, FXI deficiency, platelet disorders, or known acquired or inherited thrombophilia etc.) other than congenital Hemophilia A or B with or without inhibitors
- History of angina pectoris or treatment for angina pectoris
- History of coronary and/or peripheral atherosclerotic disease, congestive heart failure, disseminated intravascular coagulopathy, or stage 2 hypertension defined as systolic blood pressure (SBP) ≥160 mmHg or diastolic blood pressure (DBP) ≥100 mmHg even if controlled
- History of thrombophlebitis, venous/arterial thromboembolic diseases (particularly deep vein thrombosis, pulmonary embolism, stroke, myocardial infarction, cerebrovascular accident, ischemic heart disease, transient ischemic attack)
- Known or suspected hypersensitivity of the immune system, history of anaphylactic reaction, known severe allergies, non-allergic drug reactions, or multiple drug
allergies
- Subjects with inhibitors treated with FEIBA, who are not willing to accept rFVIIa (NovoSeven) for the treatment of any bleeds occurring either between screening and dosing or after study drug administration, and until the end of the study.