Mesenchymal stem cell therapy for MS – results of international trial

The international MESEMS trial, which recently reported its final results, showed that mesenchymal stem cell therapy was safe and well tolerated by people with MS, but was not effective at reducing inflammation in people with active forms of MS.

What is MSC therapy?

Mesenchymal stem cells (MSCs – sometimes referred to as mesenchymal stromal cells or bone marrow stromal cells) are adult stem cells that can produce many different types of cells, including muscle, cartilage and nerve cells.

MSC therapy involves isolating MSCs from the bone marrow. These cells are multiplied in the laboratory (a process that takes a few weeks) and then infused back into the blood or spinal fluid of the person undergoing therapy.

At present, there isn’t enough evidence to recommend this type of treatment for people with MS and it should only be offered as part of a clinical trial.

Why are researchers interested in MSC therapy?

Research from animal studies and very early stage human trials suggested that MSCs could improve neurological function and have a positive effect on the immune system. These early phase trials with small numbers of patients also did not report any serious adverse events or deaths. However, despite reports and case studies of patients that may have received some early or temporary benefits, there is not yet sufficient evidence to conclude whether there is any benefit or improvement at all in MS.

What was the MESEMS trial?

The MESEMS (mesenchymal stem cells for MS) trial, which was partly funded by MSIF, took place in centres in North America, Europe and Australia. These different research groups used the same clinical trial protocol, which allows independent small trials to be combined for a more robust result. 144 people took part in the trial – the majority had relapsing MS, but a small number had active progressive MS. The study, which recently reported its final results, showed that MSC therapy was safe and well tolerated by people with MS, but was not effective at reducing inflammation in people with active forms of MS.

What happens next?

This may not be the final word on MSC therapy for MS. It is not certain whether the negative outcome from the MESEMS trial means the therapy is not actually effective, or reflects aspects of the trial methodology, such as participants having different types. As mentioned above, in animal and early stage studies, MSCs have demonstrated neuroprotective properties, and researchers believe further investigation is needed to assess whether MSCs might be able to repair damaged tissue. How MSC therapy is delivered to the person, sources of MSCs and doses of the treatment are all areas for future study.