Safety and Efficacy of Intravenous Natalizumab in Acute Ischemic Stroke

Key Inclusion Criteria:

- Clinical diagnosis of supratentorial acute ischemic stroke defined by LKN ≤24 hours
prior to study treatment initiation.

- Score of 5 to 23 points, inclusive, on the NIHSS at Screening for subjects initiating
treatment ≤9 hours from LKN. Note: NIHSS eligibility must be confirmed within 60
minutes prior to randomization.

- Score of 5 to 15 points, inclusive, on the NIHSS at Screening for subjects initiating
treatment >9 to ≤24 hours from LKN. Note: NIHSS eligibility must be confirmed within
60 minutes prior to randomization.

- Prior to index stroke, patient was able to perform basic activities of daily living
without assistance: dressing, eating, walking, bathing, and using the toilet.

- For those subjects who underwent a cranial MRI, there is at least 1 acute infarct with
a diameter of ≥2 cm on baseline brain diffusion-weighted imaging.

Key Exclusion Criteria:

- Lacunar or isolated brainstem or cerebellar stroke based on clinical assessment and
available acute imaging studies performed under the standard of care.

- Presence of acute intracranial hemorrhage on acute brain CT or MRI. However, petechial
hemorrhages of ≤1 cm are not exclusionary.

- Severe stroke defined by imaging criteria based on either one of the following:

- Alberta Stroke Program Early CT (ASPECT) score of 0 to 4 based on head CT or

- Acute infarct volume on MRI diffusion weighed imaging greater than or equal to 70 mL

- Seizure at the onset of stroke.

- Known history of prior treatment with natalizumab.

- Known history of active viral hepatitis B or C.

- Signs and symptoms of active or acute infection.

NOTE: Other protocol-defined inclusion/exclusion criteria may apply.