1. Massive confirmed pulmonary embolism (PE) with haemodynamic instability at trial entry 2. Patients on mechanical ventilation for longer than 48 hours 3. Chronic pulmonary disease i.e. with known forced expiratory volume in 1 second (FEV1) <50% requiring home oxygen, or oral steroid therapy or hospitalisation for exacerbation within 12 months, or significant chronic pulmonary disease in the Investigator’s opinion, or primary pulmonary arterial hypertension 4. Has a Do-Not-Intubate (DNI) or Do-Not-Resuscitate (DNR) order 5. In the opinion of the investigator, is not expected to survive for > 48 hours after admission 6. Patients with known hypersensitivity to the active substance alteplase, gentamicin (a trace residue from the manufacturing process) or to any of the excipients 7. Significant bleeding disorder at present or within the past 3 months, known haemorrhagic diathesis 8. Patients receiving effective oral anticoagulant treatment, e.g. vitamin K antagonists with INR >1.3, or any direct oral anticoagulant within the past 48 hours 9. Any history of central nervous system damage (i.e. neoplasm, aneurysm, intracranial or spinal surgery) 10. History or evidence or suspicion of intracranial haemorrhage including sub-arachnoid haemorrhage 11. Severe uncontrolled arterial hypertension (according to the investigator`s judgement) 12. Major surgery or significant trauma in the past 10 days, recent trauma to head or cranium 13. Cardiac arrest and/or cardiopulmonary resuscitation during the current hospital stay 14. Obstetrical delivery within the past 10 days 15. Severe hepatic dysfunction, including biopsy confirmed hepatic cirrhosis, portal hypertension, hepatic encephalopathy, or active hepatitis 16. Bacterial endocarditis, pericarditis 17. Acute pancreatitis 18. Documented ulcerative gastro-intestinal disease during the last 3 months 19. Severe heart failure (New York Heart Association Class IV) 20. Arterial aneurysms, arterial/venous malformations 21. Malignancy (Stage IV) 22. Haemorrhagic stroke or stroke of unknown origin at any time 23. Ischaemic stroke or transient ischaemic attack (TIA) in the preceding 6 months Further criteria apply.

1. Massive confirmed pulmonary embolism (PE) with haemodynamic instability at trial entry 2. Patients on mechanical ventilation for longer than 48 hours 3. Chronic pulmonary disease i.e. with known forced expiratory volume in 1 second (FEV1) <50% requiring home oxygen, or oral steroid therapy or hospitalisation for exacerbation within 12 months, or significant chronic pulmonary disease in the Investigator’s opinion, or primary pulmonary arterial hypertension 4. Has a Do-Not-Intubate (DNI) or Do-Not-Resuscitate (DNR) order 5. In the opinion of the investigator, is not expected to survive for > 48 hours after admission 6. Patients with known hypersensitivity to the active substance alteplase, gentamicin (a trace residue from the manufacturing process) or to any of the excipients 7. Significant bleeding disorder at present or within the past 3 months, known haemorrhagic diathesis 8. Patients receiving effective oral anticoagulant treatment, e.g. vitamin K antagonists with INR >1.3, or any direct oral anticoagulant within the past 48 hours 9. Any history of central nervous system damage (i.e. neoplasm, aneurysm, intracranial or spinal surgery) 10. History or evidence or suspicion of intracranial haemorrhage including sub-arachnoid haemorrhage 11. Severe uncontrolled arterial hypertension (according to the investigator`s judgement) 12. Major surgery or significant trauma in the past 10 days, recent trauma to head or cranium 13. Cardiac arrest and/or cardiopulmonary resuscitation during the current hospital stay 14. Obstetrical delivery within the past 10 days 15. Severe hepatic dysfunction, including biopsy confirmed hepatic cirrhosis, portal hypertension, hepatic encephalopathy, or active hepatitis 16. Bacterial endocarditis, pericarditis 17. Acute pancreatitis 18. Documented ulcerative gastro-intestinal disease during the last 3 months 19. Severe heart failure (New York Heart Association Class IV) 20. Arterial aneurysms, arterial/venous malformations 21. Malignancy (Stage IV) 22. Haemorrhagic stroke or stroke of unknown origin at any time 23. Ischaemic stroke or transient ischaemic attack (TIA) in the preceding 6 months Further criteria apply.