Stem cell line shows potential in helping recover motor function after a stroke

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Stem cell line shows potential in helping
recover motor function after a stroke

DURHAM: Results of a phase 1 clinical trial released recently in STEM CELLS Translational Medicine (SCTM) have identified a specific line of human neural stem cells that shows potential for helping recover motor function in those who suffer a hemiparetic stroke (where one side of the body is left weak or paralyzed).

NSI-566 human neural stem cells were implanted adjacent to the stroke lesion in nine subjects at doses up to 72 million cells per subject, and subjects were followed for 24 months. Cells appeared to survive long-term, and patients in the single-arm trial showed improvements in motor function following cell transplantation. This indicates the procedure is safe and may have potential to provide benefit to patients with motor deficits from stroke.

Strokes are a major cause of prolonged neurological disability worldwide, particularly in China and other Asian countries. No effective therapies currently exist that will reverse it. Several different cell types have been proposed and tested in preclinical models and clinical trials to treat neurological conditions, but few have shown significant properties to differentiate into genuine brain cells or the capability to integrate into central nervous system tissue.

One cell type that has been exhibiting some success is the NSI-566 cell line from Neuralstem, Inc. NSI-566 is an epigenetically expanded line of primary human neural stem cells isolated from a single fetal spinal cord tissue. Ongoing clinical trials in the U.S. for treating amyotrophic lateral sclerosis and spinal cord injury have provided evidence that NSI-566 can survive in patients for at least 2.5 years and may have the potential to provide clinical benefit. To date, there have been no major side effects reported.

That information prompted the research team led by Karl K. Johe, Ph.D., of Neuralstem, and Ruxiang Xuu, M.D., of the Affiliated BaYi Brain Hospital, of Army General Hospital of PLA in Beijing to ponder whether NSI-566 might help stroke patients, too.

“To the best of our knowledge, this is the first study to assess the feasibility and safety of transplanting non-immortalized human neural stem cells into stroke brain in chronic stage. Another objective was to determine the maximum tolerated dose into the peri-infarct sites in these patients,” Dr. Johe said.

Nine men and women between the ages of 30 and 65 were selected for the study. All had some level of hemiparesis due to stroke. Eight experienced moderate impairment (they required some help but were able to walk without assistance), while the ninth was moderately severe (unable to walk without assistance and could not self-care). Subjects were given NSI-566 between five and 24 months after the time of stroke.

The patients were divided into three equal groups, with each group administered a different dose of the stem cell line. The patients were then followed for 24 months.

“At the end of that period, we saw that transplantation of the NSI-566 cells was being well tolerated and it suggested preliminary clinical benefits. Results from imaging studies indicate new neural tissue formation in the stem cell implantation area of all nine patients,” noted Dr. Xu.

Dr. Johe added, “The results suggest that grafted NSI-566 continue to survive in the stroke lesion long after cessation of immunosuppressant, and that the potential clinical effects persist throughout the 24-month observation period. Although this was a small, one-arm study of feasibility, the results are encouraging to warrant further studies,” he concluded.

“With strokes as a major cause of neurological disability and no therapies available to fully reverse their effects, this pilot study of a cell-based therapy is promising,” said Anthony Atala, M.D., Editor-in-Chief of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine. “In this study, the therapy doses were well tolerated by the patients who all showed improvement in their condition. Larger clinical studies will be welcomed to further verify the safety and efficacy of this treatment.”

Ref.: “Stable Intra cerebral Transplantation of Neural Stem Cells for the Treatment of Paralysis Due to Ischemic Stroke,” can be accessed at https://stemcellsjournals.onlinelibrary.wiley.com/doi/abs/10.1002/sctm.18-0220.

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