This trial is conducted in Europe and Japan. The aim of this trial is to assess the safety and pharmacokinetics (the rate at which the body eliminates the trial drug) of single doses of NNC128-0000-2011, when administered i.v. (intravenously) to haemophilia patients.

Inclusion Criteria:

• Patients diagnosed with haemophilia A or B (with or without inhibitors and irrespective of severity) based on medical records
• Japan: A legally acceptable representative (LAR) is required for patients between 18 and 19 years
• Body weight less than or equal to 100.0 kg
• Body Mass Index (BMI) less than or equal to 30.0 kg/m^2

Exclusion Criteria:

• Known or suspected allergy to trial product(s) or related products (including rFVIIa)
• Previous participation in this trial defined as administration of trial product
• The receipt of any investigational product within 30 days prior to trial start (screening)
• Congenital or acquired coagulation disorders other than haemophilia A or B
• Receipt of Immune Tolerance Induction (ITI) within the last 30 days prior to screening
• Any surgery within 30 days prior to screening
• Planned surgery within the trial period
• Platelet count below 50,000 platelets/mcL (based on medical records within the last 1 month or laboratory results at screening)
• Prothrombin time (PT) above 4 times Upper limit of normal (ULN) or International normalised ratio (INR) greater than 1.7
• Hepatic dysfunction or severe hepatic disease as evaluated by the investigator (trial physician)
• Renal dysfunction (dialysis) and/or creatinine levels more than or equal to 20% above upper normal limit (according to medical records or laboratory results at screening)
• Advanced atherosclerotic disease (defined as known history of ischemic heart disease, ischemic stroke, etc.)
• Any disease, condition, or medication which, according to the investigator's (trial physician) judgement, could imply a potential hazard to the patient or interfere with the trial participation or trial outcome
• Mental incapacity, unwillingness to cooperate, or a language barrier precluding adequate understanding and cooperation