A First-in-Human, Phase I Study of Neural Stem Cell Transplantation for Chronic Spinal Cord Injury

NSI‐566 is a stable, primary adherent neural stem cell line derived from a single human fetal spinal cord and expanded epigenetically with no genetic modification. This cell line is being tested in clinical trials in the U.S. for treatment of amyotrophic lateral sclerosis and spinal cord injury. In a single‐site, phase I study, we evaluated the feasibility and safety of NSI‐566 transplantation for the treatment of hemiparesis due to chronic motor stroke and determined the maximum tolerated dose for future trials. Three cohorts (n = 3 per cohort) were transplanted with one‐time intracerebral injections of 1.2 × 107, 2.4 × 107, or 7.2 × 107 cells. Immunosuppression therapy with tacrolimus was maintained for 28 days. All subjects had sustained chronic motor strokes, verified by magnetic resonance imaging (MRI), initiated between 5 and 24 months prior to surgery with modified Rankin Scores [MRSs] of 2, 3, or 4 and Fugl‐Meyer Motor Scores of 55 or less. At the 12‐month visit, the mean Fugl‐Meyer Motor Score (FMMS, total score of 100) for the nine participants showed 16 points of improvement (p = .0078), the mean MRS showed 0.8 points of improvement (p = .031), and the mean National Institutes of Health Stroke Scale showed 3.1 points of improvement (p = .020). For six participants who were followed up for 24 months, these mean changes remained stable. The treatment was well tolerated at all doses. Longitudinal MRI studies showed evidence indicating cavity‐filling by new neural tissue formation in all nine patients. Although this was a small, one‐arm study of feasibility, the results are encouraging to warrant further studies. Stem Cells Translational Medicine 2019;8:999–1007

Section: Introductionmentioning

confidence: 79%

Section: Introductionmentioning

confidence: 93%

Stable Intracerebral Transplantation of Neural Stem Cells for the Treatment of Paralysis Due to Ischemic Stroke

Zhang

Liu

Reuss

et al. 2019

“…A range of human stem cell‐based therapy methods have been developed for clinical applications in the treatment of ischemic stroke and CNS injury . Several noninvasive methods are safe for evaluation of cell‐tracking.…”

Section: Discussionmentioning

confidence: 99%

In vivo monitoring of remnant undifferentiated neural cells following human induced pluripotent stem cell-derived neural stem/progenitor cells transplantation

Tanimoto

Yamasaki

Nagoshi

et al. 2020

Transplantation of human‐induced pluripotent stem cell‐derived neural stem/progenitor cells (hiPSC‐NS/PCs) is a promising treatment for a variety of neuropathological conditions. Although previous reports have indicated the effectiveness of hiPSC‐NS/PCs transplantation into the injured spinal cord of rodents and nonhuman primates, long‐term observation of hiPSC‐NS/PCs post‐transplantation suggested some “unsafe” differentiation‐resistant properties, resulting in disordered overgrowth. These findings suggest that, even if “safe” NS/PCs are transplanted into the human central nervous system (CNS), the dynamics of cellular differentiation of stem cells should be noninvasively tracked to ensure safety. Positron emission tomography (PET) provides molecular‐functional information and helps to detect specific disease conditions. The current study was conducted to visualize Nestin (an NS/PC marker)‐positive undifferentiated neural cells in the CNS of immune‐deficient (nonobese diabetic‐severe combined immune‐deficient) mice after hiPSC‐NS/PCs transplantation with PET, using 18 kDa translocator protein (TSPO) ligands as labels. TSPO was recently found to be expressed in rodent NS/PCs, and its expression decreased with the progression of neuronal differentiation. We hypothesized that TSPO would also be present in hiPSC‐NS/PCs and expressed strongly in residual immature neural cells after transplantation. The results showed high levels of TSPO expression in immature hiPSC‐NS/PCs‐derived cells, and decreased TSPO expression as neural differentiation progressed in vitro. Furthermore, PET with [18F] FEDAC (a TSPO radioligand) was able to visualize the remnant undifferentiated hiPSC‐NS/PCs‐derived cells consisting of TSPO and Nestin+ cells in vivo. These findings suggest that PET with [18F] FEDAC could play a key role in the safe clinical application of CNS repair in regenerative medicine.

“…Glia limitans‐forming astrocytes have been reported to selectively express the superoxide dismutase (SOD) . SOD expression is not seen in parenchymal astrocytes . Therefore, we next tested if the hNSC‐derived astrocytes in the glia limitans also overexpressed SOD.…”

Section: Resultsmentioning

confidence: 99%

Spinal parenchymal occupation by neural stem cells after subpial delivery in adult immunodeficient rats

Maršala

Kamizato

Tadokoro

et al. 2019

Self Cite

Neural precursor cells (NSCs) hold great potential to treat a variety of neurodegenerative diseases and injuries to the spinal cord. However, current delivery techniques require an invasive approach in which an injection needle is advanced into the spinal parenchyma to deliver cells of interest. As such, this approach is associated with an inherent risk of spinal injury, as well as a limited delivery of cells into multiple spinal segments.Here, we characterize the use of a novel cell delivery technique that employs single bolus cell injections into the spinal subpial space. In immunodeficient rats, two subpial injections of human NSCs were performed in the cervical and lumbar spinal cord, respectively. The survival, distribution, and phenotype of transplanted cells were assessed 6-8 months after injection. Immunofluorescence staining and mRNA sequencing analysis demonstrated a near-complete occupation of the spinal cord by injected cells, in which transplanted human NSCs (hNSCs) preferentially acquired glial phenotypes, expressing oligodendrocyte (Olig2, APC) or astrocyte (GFAP) markers. In the outermost layer of the spinal cord, injected hNSCs differentiated into glia limitans-forming astrocytes and expressed human-specific superoxide dismutase and laminin. All animals showed normal neurological function for the duration of the analysis. These data show that the subpial cell delivery technique is highly effective in populating the entire spinal cord with injected NSCs, and has a potential for clinical use in cell replacement therapies for the treatment of ALS, multiple sclerosis, or spinal cord injury. K E Y W O R D S glia limitans formation from grafted neural precursors, human-specific mRNA sequencing, immunodeficient rat, neuraxial neural precursor migration, subpial stem cell injection 1 | BACKGROUND The use of spinally targeted cell-replacement therapies for the treatment of a variety of neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and spinal cord injury (SCI), has recently reached the clinical trial stage with several phase I or phase II trials underway.Extensive preclinical studies in rodent and large animal models of ALS and SCI have tested several spinal cell delivery techniques to define the most effective and safe cell delivery approach to be used in human clinical trials.