Activated Protein C in Acute Stroke Trial

Inclusion Criteria: * Symptoms of acute ischemic stroke; acute ischemic stroke is defined as the sudden onset of a measurable neurological deficit presumably attributable to focal cerebral ischemia, and otherwise not attributable to ICH or other disease process * Symptom onset within 0-9 hours of administration of study medication Stroke onset is defined as the time of first symptoms or signs of neurologic deficit. If the onset of symptoms/signs is unwitnessed, time of onset is presumed to be the last time the patient was observed to be intact * Neurologic deficit on examination with NIHSS of greater than 4 and less than 23 * In women of childbearing potential, a negative urine pregnancy test prior to enrollment (to be confirmed later by serum test) * Signed informed consent by subject or authorized representative Exclusion Criteria: * Computed tomography scan of the brain with evidence of intracranial hemorrhage or any finding not consistent with acute ischemic stroke as cause of presenting symptoms * CT imaging demonstrating hypodensity more than 1/3 of MCA territory or mass effect * Neurological (other than presenting stroke) or psychiatric condition that may affect the patient's functional status or that may interfere with the patient's assessment * Clinically relevant pre-existing neurological deficit (historical modified Rankin score greater than 2 regardless of cause) * Treatment with tissue plasminogen activator or other thrombolytic agent within 3 months, including treatment with tissue plasminogen activator for current stroke * Need for treatment with anti-platelet agent or anticoagulant within 36 hours * Previous stroke or serious head trauma within 3 months * Major surgery within previous 14 days * History of intracranial hemorrhage * Rapidly improving or minor symptoms * Symptoms suggestive of subarachnoid hemorrhage * Gastrointestinal hemorrhage or urinary tract hemorrhage within previous 21 days * Arterial puncture at noncompressible site within the previous 7 days * Seizure at onset of stroke * Use of oral anticoagulant medications at time of symptom onset or treatment with subcutaneous or intravenous heparin within previous 48 hours with elevated partial thromboplastin time * INR values greater than 1.5 * Platelet count less than 100,000/μL * Glucose concentration less than 40 mg/dL or greater than 400mg/dL * Participation in another clinical trial within the last 30 days, or planned participation in another clinical trial * Women who are currently breast-feeding * Known resistance to activated Protein C (Factor V Leiden mutation)