In a small, phase II study of blood stem cell transplantation in people with relapsing or secondary-progressive forms of multiple sclerosis, disease activity on MRI scans was reduced significantly more than the disease-modifying therapy mitoxantrone. Larger, well-controlled clinical trials are needed to determine whether this experimental approach will prove to be a safe and effective solution for people with MS. Giovanni Mancardi, MD (University of Genoa) and colleagues in the Autologous Haematopoietic Stem Cell Transplantation Trial in MS (ASTIMS) study group report in Neurology (Published online February 11, 2014). This study was sponsored by the Italian MS Association.
Background: One type of procedure that has been explored for many years in MS is called “autologous hematopoietic (blood cell-producing) stem cell transplantation” – or HSCT. This procedure has been used in attempts to “reboot” the immune system, which launches attacks on the brain and spinal cord in people with MS.
In HSCT, these stem cells (derived from a person’s own bone marrow or blood) are stored, and the rest of the individual’s immune cells are depleted usually by chemotherapy. Then the stored stem cells are reintroduced back to the individual’s bloodstream. The new stem cells migrate to the bone marrow and over time produce new cells. Eventually they repopulate the body with immune cells. The goal of this currently experimental procedure is that the new immune cells will no longer attack myelin or other brain tissue, providing the person, what is hoped to be, a completely new immune system.
The Study: Investigators enrolled 21 people with relapsing-remitting or secondary-progressive MS who had experienced disease worsening in the past year despite taking disease-modifying therapies. Nine participants received HSCT after a regimen of treatments that suppress the immune system, and a comparison group of 12 people received treatment with mitoxantrone 20 mg/month for six months. Mitoxantrone is a powerful immune system-suppressing drug that is approved for use in people with secondary-progressive, progressive-relapsing, or worsening relapsing-remitting MS. Participants were followed for four years.
The primary endpoint tested in this study was measurement of new disease activity on MRI scans at four years, and other endpoints including relapse rates and progression of disability.
Results: MRI scan results after four years were available from 17 participants, and suggested that stem cell therapy did a better job of suppressing disease activity. The cumulative number of new brain lesions was 79% less in the stem cell group compared to the mitoxantrone group. No new active (“gadolinium enhancing”) lesions appeared on MRI scans in the stem cell group, while 56% of the mitoxantrone group had new active lesions. Clinical results were available from 20 trial participants, and showed significant reductions in relapse rates in the stem cell group versus mitoxantrone. There were no statistically significant differences between the treatment groups in terms of the amount of progression experienced during the trial and after four years.
Several serious adverse events occurred in the stem cell group, including sepsis (blood infection), slowed heart rate, and systemic fungal infection. All resolved, and there were no deaths. Those on mitoxantrone also experienced adverse events including decreased white blood cells, anemia and disruption of menstruation. Adverse events occurred in 80% of all participants.
Comment: “This study contributes to our knowledge of the potential of blood stem cell therapy for the treatment of multiple sclerosis,” noted Bruce Bebo, PhD, Executive Vice President of Research at the National MS Society. “Larger, well-controlled clinical trials will need to be performed before we can know the full potential of this promising stem cell approach to MS treatment.”
There are significant risks involved in hematopoietic stem cell transplantation, and it’s important that studies such as this one be conducted to ensure that this will be a safe solution for people with MS, with significant clinical benefit.
With the urgent need for more effective treatments for MS, particularly for those with more progressive forms of the disease, the National MS Society believes that the potential of all types of cell therapies must be explored. The Society is currently supporting 15 research projects exploring various types of stem cells, including cells derived from bone marrow, fat and skin, and has supported 70 stem cell studies over the past 10 years.
Read more about research in stem cells and MS
Read more about available therapies for MS