The primary objective of this study is to evaluate the functional recovery based on Barthel index (BI) and modified Rankin Scale (mRS) while the secondary objectives are to assess the survival and re-admission rate as well as to investigate the inflammatory response in a subclinical study within 1 year of Neuroncell-EX infusion in participants with acute ischemic stroke.

Background: Ischemic stroke is a serious cerebrovascular disease with high morbidity and disability worldwide. Despite the great efforts that have been made, the prognosis of stroke patients remains unsatisfactory. Mesenchymal stem cells (MSCs) therapy is an emerging treatment studied in various medical conditions including autoimmune, inflammatory as well as central nervous system diseases. The mechanism of MSCs in the treatment of ischemic stroke involved with immune regulation, neuroprotection, angiogenesis, and neural circuit reconstruction. A large number of preclinical data have proved the feasibility of MSCs in the treatment of stroke where the administration of MSCs can alleviate neurological deficits. Similarly, a number of clinical trials have also proved the effectiveness and safety of MSCs in the treatment of stroke. Among these is a phase 2, single-center, assessor-blinded randomized controlled study by investigators using bone marrow-derived MSCs in patients with subacute middle cerebral artery infarct. The investigators demonstrated the safety, tolerability, and efficacy of intravenous infusion of MSCs with significant improvement in median infarct volume (Law et al., 2021).

Objective: To determine the efficacy of intravenous infusion of allogeneic Cytopeutics umbilical cord mesenchymal stem cells (Neuroncell-EX) in participants with acute ischemic stroke.

Study Design: This is a phase II-III double-blind randomized controlled study involving 80 participants, diagnosed with acute ischemic stroke admitted to HCTM-UKM. Investigational treatment arm (Group A-MSCs) consist of 40 participants will receive Neuroncell-EX whereas control treatment arm (Group B-Control) consist of 40 participants will receive placebo. Both groups will also receive standard medical care for acute stroke. Efficacy assessments will include Barthel index (BI) and modified Rankin Scale (mRS), Functional Magnetic Resonance Imaging (fMRI) and blood tests including biomarkers within 12 months follow-up.

Inclusion Criteria:

1. Patients must be aged ≥ 18 years old.
2. Patients with acute ischemic stroke symptom onset within 4 weeks.
3. Patients diagnosed with "moderate to severe" based on NIHSS (6-24) at the time of recruitment.
4. Patients who are not eligible for thrombolysis or thrombectomy.
5. Written informed consent by the patient or next-of-kin.

Exclusion Criteria:

1. Patients who are medically unfit such as those who are haemodynamically unstable or whose general condition is deteriorating.
2. Patients with transient ischemic attack (TIA).
3. Patients who have been diagnosed with malignancy (past or present) or primary haematological disorders.
4. Patients who have renal impairment with serum creatinine more than 200 µmol/l or creatinine clearance less than 30 ml/min.
5. Patients who have liver impairment with serum aspartate transaminase (AST) and alanine aminotransferase (ALT) two times greater than upper normal limit.
6. Patients who are pregnant or are breastfeeding.
7. Patients diagnosed with brain hemorrhage or other pathological brain disorders such as vascular malformation (brain arteriovenous malformation), tumor, abscess, cardiogenic, inflammatory and infectious cerebral embolism or other common non- ischemic brain diseases, or diagnosed with severe brain atrophy, as determined by CT or MRI scans.
8. Patients diagnosed/suspected diagnosis with acute coronary syndrome.
9. Patients with congestive cardiac failure.
10. Patients with history of confirmed or suspected pulmonary embolism or chronic obstructive pulmonary disease (COPD).
11. Patients with mental, cognitive or psychological disorders that affects their understanding and adherence to research procedures and follow-ups.
12. Patients that are undergoing experimental drug or instrument testing or have participated in other clinical drug trials in the past 3 months.