A preliminary clinical trial shows that stem cell transplantation, along with a tolerable dose of chemotherapy, is safe and more effective at slowing down multiple sclerosis (MS) than other existing therapies.

MS is a chronic neurodegenerative condition affecting about 400,000 individuals in the US and over 2 million people across the globe. According to the new clinical trial, 85% of these people have so-called relapse-remitting MS. This means that their symptoms often worsen during flare-up periods, but they also alternate with remission phases.

In MS, the body's immune system does not recognize its own central nervous system, so it attacks myelin, the protective sheath around nerve cells. While there is no known cure for MS, current treatment includes so-called disease-modifying therapies, such as interferons, glatiramer acetate, or monoclonal antibodies, which reduce inflammation and slow down the disease. However, these therapies are not entirely effective. The latest trial also notes that after 2 years of treatment, between 30% and 50% of people have "no evidence of disease activity." After 4 years of treatment, this drops to 18%.

This new research suggests that stem cell therapy may be a more effective way of slowing down the progression of the disease. The trial was led by Dr. Richard K. Burt, from the Division of Immunotherapy at the Northwestern University Feinberg School of Medicine in Chicago, IL. The team set out to compare the effect of stem cell transplantation with that of conventional disease-modifying therapies on MS progression. Dr. Burt and his colleagues published the results of their trial in the journal JAMA.

Stem cell transplant 'more effective'

As Dr. Burt and his colleagues explain in their paper, "hematopoietic stem cell transplantation" aims to eliminate "autoreactive" lymphocytes—one of the main type of immune cells in the human body—and "restart a new immune system in a non-inflammatory environment." According to the paper, previous case studies have found that 70% of those who benefited from a stem cell transplant experienced disease-free remission for 4 years.

For the current trial, the scientists recruited 110 patients from four medical centers across the US between 2005 and 2016. The trial participants were 18–55 years old and had "highly active" relapse-remitting MS. Dr. Burt and team randomly assigned these participants to receive either disease-modifying therapy, as recommended by their neurologist, or stem cell transplantation. The second group received a stem cell transplant in a "non-myeloablative regimen," which means that they also received a lower, more tolerable dose of chemotherapy.

The main outcome monitored by the researchers was disease progression. They also examined the participants' neurologic disability, their quality of life, time to relapse, and evidence of disease activity.

Overall, stem cell transplantation "was more effective than disease-modifying therapy for patients with relapsing-remitting MS," report the researchers. Stem cell therapy resulted in "prolonged time to disease progression." The therapy also improved other outcomes, including the participants' daily functioning, quality of life, and neurological functioning.

However, "further research is needed to replicate these findings and to assess long-term outcomes and safety," caution the researchers. "To our knowledge," they write, "this is the first randomized trial of [stem cell transplantation] in patients with relapsing-remitting MS."