Inclusion Criteria:

• Age 18-80
• GCS < 14 or a NIHSS > 6
• Spontaneous supratentorial ICH > 25cc
• Symptoms less than 12 hours prior to diagnostic CT scan (an unknown time of symptom onset is exclusionary)
• First dose can be given within 36 hours of symptom onset (plus a 2-hour feasibility window with approval from the coordinating center, reserved for only those situations where the patient is eligible, consented, stable but personnel scheduling prohibits giving the first dose within the 36-hour window)
• Six-hour clot size equal to the most previous clot size + 5 cc (as determined by an additional CT scan at least 6 hours after the initial stability scan (A*B*C)/2 method)
• SBP < 200 mmHg sustained for 6 hours
• Historical Rankin score of 0 or 1
• Negative pregnancy test

Exclusion Criteria:

• Infratentorial hemorrhage (any involvement of the midbrain or lower brainstem as demonstrated by radiograph or complete third nerve palsy)
• Patients with platelet count < 100,000, INR > 1.7, PT > 15s, or an elevated APTT (reversal of coumadin is permitted but the patient must not require coumadin during the acute hospitalization), Irreversible coagulopathy either due to medical condition or prior to randomization
• Clotting disorders
• Any concurrent serious illness that would interfere with the safety assessments including hepatic, renal, gastroenterologic, respiratory, cardiovascular, endocrinologic, immunologic, and hematologic disease
• Patients with a mechanical valve
• Patients with unstable mass or evolving intracranial compartment syndrome
• Ruptured aneurysm, AVM, vascular anomaly
• Greater than 80 years (higher incidence of amyloid)
• Under 18 years of ag e (high incidence of occult vascular malformation)
• Pregnant (positive pregnancy test) or lactating females (likelihood of altered coagulation function associated with the high estrogen/progesterone state)
• Irreversibly impaired brainstem function (bilateral fixed, dilated pupils and extensor motor posturing), GCS less than or equal to 4
• Historical Rankin score greater than or equal to 2
• Intraventricular hemorrhage requiring external ventricular drainage
• Internal bleeding, involving retroperitoneal sites, or the gastrointestinal, genitourinary, or respiratory tracts
• Superficial or surface bleeding, observed mainly at vascular puncture and access sites (e.g., venous cutdowns, arterial punctures) or site of recent surgical intervention
• Known risk for embolization, including history of left heart thrombus, mitral stenosis with atrial fibrillation, acute pericarditis, and subacute bacterial endocarditis
• In the investigator's opinion, the patient is unstable and would benefit from a specific intervention rather than supportive care plus or minus MIS+rtPA
• Prior enrollment in the study
• Any other condition that the investigator believes would pose a significant hazard to the subject if the investigational therapy were initiated
• Participation in another simultaneous trial of ICH treatment.