Efficacy and Safety of Intravenous Mesenchymal Stem Cells for Ischemic Stroke.

Objective: To test whether autologous modified mesenchymal stem cells (MSCs) improve recovery in patients with chronic major stroke.
Methods: In this prospective, open-label, randomized controlled trial with blinded outcome evaluation, patients with severe middle cerebral artery territory infarct within 90 days of symptom onset were assigned, in a 2:1 ratio, to receive preconditioned autologous MSC injections (MSC group) or standard treatment alone (control group). The primary outcome was the score on the modified Rankin Scale (mRS) at 3 months. The secondary outcome was to further demonstrate motor recovery.
Results: A total of 39 and 15 patients were included in the MSC and control groups, respectively, for the final intention-to-treat analysis. Mean age of patients was 68 (range 28-83) years, and mean interval between stroke onset to randomization was 20.2 (range 5-89) days. Baseline characteristics were not different between groups. There was no significant difference between the groups in the mRS score shift at 3 months ( p = 0.732). However, secondary analyses showed significant improvements in lower extremity motor function in the MSC group compared to the control group (change in the leg score of the Motricity Index, p = 0.023), which was notable among patients with low predicted recovery potential. There were no serious treatment-related adverse events.
Conclusions: IV application of preconditioned, autologous MSCs with autologous serum was feasible and safe in patients with chronic major stroke. MSC treatment was not associated with improvements in the 3-month mRS score, but we did observe leg motor improvement in detailed functional analyses.
Classification of Evidence: This study provides Class III evidence that autologous MSCs do not improve 90-day outcomes in patients with chronic stroke.
Clinicaltrialsgov Identifier: NCT01716481.
(© 2021 American Academy of Neurology.)