Trial of PCSK9 Inhibition in Patients with Acute Stroke and Symptomatic Intracranial Atherosclerosis

Inclusion Criteria: * Clinical diagnosis of ischemic stroke with National Institutes of Health Stroke Scale (NIHSS) score of 1-15 * Ischemic lesions on diffuse-weighted imaging located in the territory of symptomatic intracranial atherosclerosis (ICAS). * Symptomatic ICAS (above 30%) at the M1 or M2 of the middle cerebral artery, basilar artery or at the intracranial portion of the internal carotid artery or vertebral artery. * Serum LDL-C ≥70 mg/dL for subjects on lipid-lowering therapies (such as a statin and/or ezetimibe) or LDL-C ≥100 mg/dL for subjects without lipid-lowering therapies. * Ability to randomize within 7 days of time last known free of new ischemic symptoms. * Ability to receive alirocumab or statin treatment within 7 days of stroke onset. * Head CT or MRI ruling out hemorrhage or other pathology, such as vascular malformation, tumor, or abscess, that could explain symptoms or contraindicate therapy. * Pre-stroke modified Rankin Scale (mRS)≦2 Exclusion Criteria: * Age \<20 years. * Judged by clinical physician. * After endovascular intervention or endarterectomy for the symptomatic ICAS. * Patients with more than 50% stenosis of extra-cranial arteries the relevant arteries on magnetic resonance angiography (MRA), including extra-cranial carotid artery or vertebral arteries. * Patients with high risk of cardioembolic source, such as atrial fibrillation, acute myocardial infarction, severe heart failure or valvular heart disease. * Other determined stroke e…