Key Inclusion Criteria:  Age 18 years or older Clinical diagnosis of acute ischemic stroke with NIH Stroke Scale (NIHSS) score ≥ 6 with symptom onset (or last seen normal) up to 24 hours Large vessel occlusion in the intracranial internal carotid artery (ICA), middle cerebral artery (MCA) M1 or M2 segments, basilar or vertebral artery  Key Exclusion Criteria:  Evidence of hemorrhage Significant mass effect and/or midline shift Vessel tortuosity too difficult to allow endovascular access per investigator judgment Severe or fatal co-morbidities