Stem cell therapy reduces symptoms of progressive MS for some people

After experimental stem cell therapy, people who required assistance walking due to symptoms of progressive multiple sclerosis saw their mobility improve

By Grace Wade

19 May 2023

An experimental stem cell therapy may reduce some symptoms of progressive multiple sclerosis, primarily in people with severe disability from the disease.

Multiple sclerosis (MS) is a chronic condition in which the immune system attacks the brain and spinal cord, causing difficulties with walking, memory, bladder control and other bodily functions. When symptoms gradually worsen over time, it is called progressive MS.

There is no approved treatment for progressive MS, but a few small clinical trials have previously indicated that certain kinds of stem cells may help. Our bodies produce many kinds of stem cells, which have the potential to develop into different types of specialist cells.

Mesenchymal stem cells are primarily produced in our bone marrow and can give rise to a diverse array of bone, fat, cartilage and other cells. They are also known to play a role in the body’s healing processes, including having the ability to “to signal to cells in the brain where there is tissue damage and initiate the brain’s capacity for repair”, says Violaine Harris at the Tisch MS Research Center of New York, who led this new study. That makes these kinds of cells of particular interest for treating MS.

Harris and her colleagues collected mesenchymal stem cells from 51 people with progressive MS.

The researchers coaxed these cells to generate millions more of themselves in the lab. They then injected these into the participants’ spinal fluid. Twenty-four participants received six injections of their own cells over 12 months while the rest received an equal number of saline injections.

Before and after the trial, the team assessed the severity of participants’ symptoms using the expanded disability status scale (EDSS), which measures impairments caused by MS. It ranges from 0 to 10, with higher scores representing greater disability.

All participants started with an EDSS between 3 and 6.5. There was no significant difference in average scores between the two groups by the trial’s end, but there was a significant difference on some tests, according to data presented at the American Academy of Neurology’s annual meeting in Boston on 24 April.

For example, in participants with an initial EDSS of 6 to 6.5 – meaning they require assistance walking – those receiving stem cell therapy significantly improved in walking ability compared with those in the control group. On a timed 25-foot walk test (about 7.6 metres), their time decreased by about 5 per cent, on average, whereas the control group’s increased by almost 55 per cent.

Additionally, 69 per cent of people with bladder dysfunction in the treatment group saw improvements in urine retention compared with 36 per cent of those in the control group. “This may not have been a home run in terms of clinical trials, but we learned a lot,” says Harris. This is the first clinical trial to show stem cell therapy improves symptoms of progressive MS, as previous trials only showed reductions in spinal fluid markers of the condition. But additional research is needed to elucidate why only some saw benefit. “With EDSS we didn’t see any improvement, which is not unusual for clinical trials – it’s somewhat insensitive, especially in progressive disease,” says Harris. For instance, EDSS assesses walking ability based on whether someone requires assistance – not if they see any degree of improvement.

The team’s next trial will only include people who are most likely to benefit from the therapy and will investigate upping dosage. “Based on some of our previous work, and also what others have done in the field, we think that our dosing might be too low,” says Harris.

“While the results of this study were ambiguous, we continue to believe there is great promise in cell-based therapies,” says Bruce Bebo at the National Multiple Sclerosis Society in New York.