Repeated subarachnoid administrations of allogeneic human umbilical cord mesenchymal stem cells for spinal cord injury: a phase 1/2 pilot study.

BACKGROUND AIMS: Stem cell transplantation is a potential treatment for intractable spinal cord injury (SCI), and allogeneic human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising candidate because of the advantages of immune privilege, paracrine effect, immunomodulatory function, convenient collection procedure and little ethical concern, and there is an urgent need to develop a safe and effective protocol regarding their clinical application. METHODS: A prospective, single-center, single-arm study in which subjects received four subarachnoid transplantations of hUC-MSCs (1 × 106 cells/kg) monthly and were seen in follow-up four times (1, 3, 6 and 12 months after final administration) was conducted. At each scheduled time point, safety and efficacy indicators were collected and analyzed accordingly. Adverse events (AEs) were used as a safety indicator. American Spinal Injury Association (ASIA) and SCI Functional Rating Scale of the International Association of Neurorestoratology (IANR-SCIFRS) total scores at the fourth follow-up were determined as primary efficacy outcomes, whereas these two indicators at the remaining time points as well as scores of pinprick, light touch, motor and sphincter, muscle spasticity and spasm, autonomic system, bladder and bowel functions, residual urine volume (RUV) and magnetic resonance imaging (MRI) were secondary efficacy outcomes. Subgroup analysis of primary efficacy indicators was also performed. RESULTS: Safety and efficacy assessments were performed on 102 and 41 subjects, respectively. Mild AEs involving fever (14.1%), headache (4.2%), transient increase in muscle tension (1.6%) and dizziness (1.3%) were observed following hUC-MSC transplantation and resolved thoroughly after conservative treatments. There was no serious AE. ASIA and IANR-SCIFRS total scores revealed statistical increases when compared with the baselines at different time points during the study, mainly reflected in the improvement of pinprick, light touch, motor and sphincter scores. Moreover, subjects showed a continuous and remarkable decrease in muscle spasticity. Regarding muscle spasm, autonomic system, bladder and bowel functions, RUV and MRI, data/imaging at final follow-up showed significant improvements compared with those at first collection. Subgroup analysis found that hUC-MSC transplantation improved neurological functions regardless of injury characteristics, including level, severity and chronicity. CONCLUSIONS: The authors' present protocol demonstrates that intrathecal administration of' allogeneic hUC-MSCs at a dose of 106 cells/kg once a month for 4 months is safe and effective and leads to significant improvement in neurological dysfunction and recovery of quality of life.

Subarachnoid transplantation of human umbilical cord mesenchymal stem cell in rodent model with subacute incomplete spinal cord injury: Preclinical safety and efficacy study.

Functional multipotency renders human umbilical cord mesenchymal stem cell (hUC-MSC) a promising candidate for the treatment of spinal cord injury (SCI). However, its safety and efficacy have not been fully understood for clinical translation. In this study, we performed cellular, kinematic, physiological, and anatomical analyses, either in vitro or in vivo, to comprehensively evaluate the safety and efficacy associated with subarachnoid transplantation of hUC-MSCs in rats with subacute incomplete SCI. Concerning safety, hUC-MSCs were shown to have normal morphology, excellent viability, steady proliferation, typical biomarkers, stable karyotype in vitro, and no tumorigenicity both in vitro and in vivo. Following subarachnoid transplantation of hUC-MSCs in the subject rodents, the biodistribution of hUC-MSCs was restricted to the spinal cord, and no toxicity to immune system or organ function was observed. Body weight, organ weight, and the ratio of the latter upon the former between stem cell-transplanted rats and placebo-injected rats revealed no statistical differences. Regarding efficacy, hUC-MSCs could differentiate into osteoblasts, chondrocytes, adipocytes and neural progenitor cells in vitro. While in vivo studies revealed that subarachnoid transplantation of stem cells resulted in significant improvement in locomotion, earlier automatic micturition recovery and reduced lesion size, which correlated with increased regeneration of tracking fiber and reduced parenchymal inflammation. In vivo luminescence imaging showed that a few of the transplanted luciferase-labeled hUC-MSCs tended to migrate towards the lesion epicenter. Shortened latency and enhanced amplitude were also observed in both motor and sensory evoked potentials, indicating improved signal conduction in the damaged site. Immunofluorescent staining confirmed that a few of the administrated hUC-MSCs integrated into the spinal cord parenchyma and differentiated into astrocytes and oligodendrocytes, but not neurons. Moreover, decreased astrogliosis, increased remyelination, and neuron regeneration could be observed. To the best of our knowledge, this preclinical study provides detailed safety and efficacy evidence regarding intrathecal transplantation of hUC-MSCs in treating SCI for the first time and thus, supports its initiation in the following clinical trial.

Human umbilical cord mesenchymal stem cells to treat spinal cord injury in the early chronic phase: study protocol for a prospective, multicenter, randomized, placebo-controlled, single-blinded clinical trial.

Human umbilical cord mesenchymal stem cells (hUC-MSCs) support revascularization, inhibition of inflammation, regulation of apoptosis, and promotion of the release of beneficial factors. Thus, they are regarded as a promising candidate for the treatment of intractable spinal cord injury (SCI). Clinical studies on patients with early chronic SCI (from 2 months to 1 year post-injury), which is clinically common, are rare; therefore, we will conduct a prospective, multicenter, randomized, placebo-controlled, single-blinded clinical trial at the Third Affiliated Hospital of Sun Yat-sen University, West China Hospital of Sichuan University, and Shanghai East Hospital, Tongji University School of Medicine, China. The trial plans to recruit 66 early chronic SCI patients. Eligible patients will undergo randomization at a 2:1 ratio to two arms: the observation group and the control group. Subjects in the observation group will receive four intrathecal transplantations of stem cells, with a dosage of 1 × 106/kg, at one calendar month intervals. Subjects in the control group will receive intrathecal administrations of 10 mL sterile normal saline in place of the stem cell transplantations. Clinical safety will be assessed by the analysis of adverse events and laboratory tests. The American Spinal Injury Association (ASIA) total score will be the primary efficacy endpoint, and the secondary efficacy outcomes will be the following: ASIA impairment scale, International Association of Neural Restoration-Spinal Cord Injury Functional Rating Scale, muscle tension, electromyogram, cortical motor and cortical sensory evoked potentials, residual urine volume, magnetic resonance imaging-diffusion tensor imaging, T cell subtypes in serum, neurotrophic factors and inflammatory factors in both serum and cerebrospinal fluid. All evaluations will be performed at 1, 3, 6, and 12 months following the final intrathecal administration. During the entire study procedure, all adverse events will be reported as soon as they are noted. This trial is designed to evaluate the clinical safety and efficacy of subarachnoid transplantation of hUC-MSCs to treat early chronic SCI. Moreover, it will establish whether cytotherapy can ameliorate local hostile microenvironments, promote tracking fiber regeneration, and strengthen spinal conduction ability, thus improving overall motor, sensory, and micturition/defecation function in patients with early chronic SCI. This study was approved by the Stem Cell Research Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University, China (approval No. [2018]-02) on March 30, 2018, and was registered with ClinicalTrials.gov (registration No. NCT03521323) on April 12, 2018. The revised trial protocol (protocol version 4.0) was approved by the Stem Cell Research Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University, China (approval No. [2019]-10) on February 25, 2019, and released on ClinicalTrials.gov on April 29, 2019.