Results of a clinical trial involving 10 people with secondary-progressive MS suggest that injecting a person’s own bone marrow stem cells (mesenchymal cells) appears safe and may be beneficial in helping to protect the nervous system from injury from MS. Further trials now underway should further establish the safety and potential benefit of this approach for treating MS. The study, by Drs. Peter Connick (University of Cambridge), Siddharthan Chandran (University of Edinburgh) and colleagues, was published in the February Lancet Neurology (2012; 11:150-156).
Background: There are many types of stem cells that are undergoing varying degrees of research and which are producing knowledge about their potential usefulness for treating MS. Further study is necessary to determine what kind of cells might prove optimal for treating some or all people with MS.
One approach to stem cell research in MS relates to efforts to repair nervous system damage, or to protect against the damage (neuroprotection). This research is in its infancy, and there is no evidence yet that any type of stem cells can reverse MS damage or protect against it. Adult mesenchymal (pronounced messENkimmul) stem cells are present in many tissues of the body, including the bone marrow and fat. These cells potentially have the ability both to treat immune disorders and promote tissue repair. Studies in rodent models of MS have suggested that injections of mesenchymal stem cells may have benefit, and a few trials are testing this approach in MS and in spinal cord injury.
Since there is an unmet need for therapies for progressive MS, the United Kingdom investigators chose to do this clinical trial focusing on people with secondary-progressive MS. The study was funded by many sources including the Medical Research Council, MS Society of Great Britain and Northern Ireland, and the Wellcome Trust.
The Study: Designing a clinical trial to show neuroprotection is difficult because, for one reason, the course of MS is so variable. To work around this difficulty, the research team recruited people who had very specific signs of myelin damage in the optic nerve. Participants included women and men ages 40 to 53 who had lived with MS for an average of 14.4 years. The procedure involved removing the individuals’ own bone marrow cells, which were then sorted, multiplied in lab dishes and eventually infused into the vein. Participants received a single infusion of cells based on their body weight.
The team’s primary goal was to assess feasibility and safety, but they also evaluated other outcomes such as visual function, MRI scans and disability. They observed participants for at least 12 months before the infusion and at least 6 months afterward. This small proof-of-concept trial was not placebo controlled, and the investigators compared the condition of participants for the 12 months before treatment against their condition after treatment.
Results: The procedure was found to be safe, with no serious adverse events identified. Several aspects of vision appeared to improve after treatment, including visual acuity, sensitivity to contrast, visual signal conduction (visual evoked response latency and amplitude), and optic nerve area. There was also a reduction in the rate of progression on the EDSS, a standard scale that measures physical disability. Other aspects of visual function did not change, including color vision and visual field, and imaging measures of disease activity, such as lesion volumes, retinal fiber layer thickness, and brain volume did not change significantly.
Comment: As the authors point out, the small, uncontrolled nature of the study make it important to verify the results in larger, controlled trials. In an accompanying editorial, Drs. Mark Freedman and Antonio Uccelli, who established the International Mesenchymal Stem Cell Transplantation Study Group, note that although the study is not definitive, it raises substantial interest because of the signs of repair shown in participants with secondary-progressive MS. Further trials now underway should further establish the safety and potential benefit of this approach for treating MS.
This study emphasizes the importance of research to restore function in MS by repairing and protecting the nervous system. Read more (broken link).