The STem Cell-derived Extracellular Vesicle Therapy In Acute Ischemic Stroke (STEVIA)

The study aims to assess the safety, tolerability, and preliminary efficacy of allogeneic Wharton's jelly-mesenchymal stem cell-derived extracellular vesicles (EVs) in patients with acute ischemic stroke.

Inclusion criteria

• Adults with 19 years or older
• Patients within 5 days of symptom onset who have not received thrombolytic therapy or undergone endovascular reperfusion procedures.
• Patients within 5 days of symptom onset who have received thrombolytic therapy or undergone endovascular reperfusion procedures but show no clinical recovery after 2 days of observation.
• Imaging findings must meet both of the following:

• Infarction within the middle cerebral artery territory on diffusion-weighted imaging (DWI)
• Infarct size ≥ 20 mm in the longest diameter on DWI
• Neurological status meeting all three of the following NIHSS criteria:

• Moderate to severe neurological deficit (NIHSS score between 5-21)
• New onset of motor weakness (score 2-4 in at least one of NIHSS items 5a, 5b, 6a, or 6b)
• No impaired consciousness (score 0-1 on NIHSS items 1a, 1b, and 1c)
• Voluntary written informed consent

Exclusion criteria

Subjects are ineligible if they meet any of the following:

• Pre-stroke disability (pre-stroke mRS ≥ 2)
• Likely to recover spontaneously, based on all three of:

• No longer meeting the NIHSS inclusion criteria 48 hours post-thrombolysis or endovascular therapy
• Lacunar stroke due to small vessel occlusion
• SAFE (Shoulder Abduction and Finger Extension) score ≥ 5
• Presence or risk of malignant middle cerebral artery infarction with brain edema
• Significant medical history within the past 5 years:

• Severe heart failure
• Severe infectious disease
• Severe hepatic failure or renal failure
• Newly diagnosed or actively treated cancer
• Any systemic disease deemed by investigator to significantly reduce life expectancy
• Any condition likely to hinder follow-up during the study
• Diagnosed severe psychiatric illness:

• Moderate or greater depression pre-stroke with functional impairment and suicide risk
• Pre-stroke dementia interfering with daily living (CDR ≥ 2)
• Contraindication to MRI (e.g., pacemaker)
• Pregnant or breastfeeding, or unwilling to use effective contraception method for 90 days after last dose.
• Participation in another clinical trial within the past 3 months
• Any other reason determined by the investigator that would prevent participation