Study Design and Population

The SONIC trial was a multicenter, randomized, double-blinded, placebo-controlled, 3-arm, phase II clinical study with blinded-end point evaluation. Seven hospitals in various regions of the Republic of Korea participated in this trial. All participating centers obtained institutional review board approval before trial initiation. Written informed consent for the trial was obtained from the legal guardians of patients before study enrollment. The current trial has been registered at ClinicalTrials.gov (eDocument 1).

Patients with acute ischemic stroke caused by large-vessel occlusion in the anterior circulation were eligible for the study if they were aged ≥19 years, were previously functionally independent, had a National Institutes of Health Stroke Scale score of ≥8 on admission, had baseline angiography results showing large-vessel occlusion, including the intracranial internal carotid artery and middle cerebral artery M1 or its equivalent M2, had a baseline noncontrast Alberta Stroke Program Early CT Score (ASPECTS) of ≥6, were eligible for ERT, and had an estimated time from stroke onset to groin puncture of <8 hours. In contrast, patients were excluded if their baseline noninvasive angiography results showed simultaneous occlusion in either both middle cerebral and anterior cerebral arteries, middle cerebral and posterior cerebral arteries, and left and right large vessels or both large vessels of the anterior and posterior circulations, indicating a high malignant potential.