• Acute focal symptoms or signs of any duration associated with imaging, pathological, or other objective evidence of arterial infarction OR clinical evidence of cerebral, spinal cord, or retinal focal arterial ischemic injury based on symptoms persisting greater than or equal to 24 hours that occurred within 30 days prior to randomization

• Index stroke is attributed to 70-99% stenosis (or flow gap on MRA) of a major intracranial artery (carotid artery, middle cerebral artery (M1 or M2), vertebral artery (V4), basilar artery, posterior cerebral artery (P1), or anterior cerebral artery (A1)) documented by CTA, MRA, or catheter angiography

• Modified Rankin Scale score of ≤ 4, at time of consent

• Ability to swallow pills

• At least 30 years of age, inclusive, at time of consent

• Subjects 30-49 years of age are required to meet at least ONE of the following additional criteria below to qualify for the study:

‣ diabetes treated with insulin for at least 15 years

⁃ at least 2 of the following atherosclerotic risk factors: hypertension (BP \> 140/90 or on antihypertensive therapy); dyslipidemia (LDL \> 130 mg /dl or HDL \< 40 mg/dl or fasting triglycerides \> 150 mg/dl or on lipid lowering therapy); smoking; non-insulin dependent diabetes or insulin dependent diabetes of less than 15 years duration; any of the following vascular events occurring in a parent or sibling who was \< 55 years of age for men or \< 65 years of age for women at the time of the event: myocardial infarction, coronary artery bypass, coronary angioplasty or stenting, stroke, carotid endarterectomy or stenting, peripheral vascular surgery for atherosclerotic disease

⁃ personal history of any of the following: myocardial infarction, coronary artery bypass, coronary angioplasty or stenting, carotid endarterectomy or stenting, or peripheral vascular surgery for atherosclerotic disease

⁃ any stenosis of an extracranial carotid or vertebral artery, another intracranial artery, subclavian artery, coronary artery, iliac or femoral artery, other lower or upper extremity artery, mesenteric artery, or renal artery that was documented by non-invasive vascular imaging or catheter angiography and is considered atherosclerotic

⁃ aortic arch atheroma documented by non-invasive vascular imaging or catheter angiography

⁃ any aortic aneurysm documented by non-invasive vascular imaging or catheter angiography that is considered atherosclerotic

• Negative pregnancy test in a female who has had any menses in the last 18 months and has not had surgery that would make her unable to become pregnant

• Subject is willing and able to return for all follow-up evaluations required by the protocol

• Subject is available by phone

• Subject understands the purpose and requirements of the study and can make him/herself understood

• Subject has provided informed consent (use of a LAR is not permitted)