A team in Spain reports results from a small clinical trial involving 9 people with relapsing MS, using their own stem cells taken from their bone marrow, called mesenchymal stem cells, in a strategy aimed at inhibiting MS immune activity and augmenting natural tissue repair processes. The researchers reported finding no serious safety concerns or uptick in disease activity. Although the results also showed no statistically significant clinical or MRI findings that would indicate benefit, this study represents a potentially important step. Sara Llufriu, MD, PhD, Albert Saiz, MD, and colleagues (University of Barcelona) have published their findings in PLoS ONE ( 9(12): e113936).
Background: There is exciting progress being made through innovative research related to the potential of many types of stem cells both for slowing MS disease activity and for repairing damage to the nervous system. There are many types of stem cells that are undergoing research and which are producing knowledge about their potential use in treating MS. Many of these studies involve adult mesenchymal stem cells, which are present in many tissues of the body, including bone marrow, fat (adipose tissue), and placenta obtained after birth. These cells are being tested for their ability both to treat immune disorders and promote tissue repair. Further study is necessary to determine whether and which cells might prove beneficial for treating people with MS.
The Study: The investigators had planned to enroll 16 participants, but enrollment slowed and was stopped at nine. Participants were people with relapsing-remitting MS who were unresponsive to conventional therapy, meaning that they had at least one relapse and/or disease activity on MRI scans in the past 12 months. Participants were randomly assigned to receive a single intravenous infusion of their own expanded mesenchymal stem cells or inactive placebo. After six months, the groups switched: those who had received stem cells were infused with placebo and those who had received placebo were infused with their own stem cells; the groups were followed for another six months.
The primary outcomes measured were the number of severe events and the effectiveness in terms of cumulative number of active (gadolinium-enhancing) lesions on MRI scans. Secondary outcomes measured included number of relapses and change in the EDSS (a scale of MS disability), immunological analyses, and quality of life.
One participant in the group taking placebo first withdrew after experiencing three relapses in the first five months. There was one severe adverse event during the study, but it was a bone fracture related to an accident and not related to treatment. Otherwise, none of the endpoints comparing the stem cell and placebo groups reached statistical significance. The investigators noted positive trends towards decreases in disease activity on MRI scans for the stem cell treatment group, and some decreases in inflammatory immune cells, but these differences did not reach statistical significance.
During stem cell treatment, there was one upper respiratory infection, one influenza virus infection and one gastroenteritis, all mild. One participant was infected with herpes labialis seven days after the first infusion and one month after the second infusion. One infusion reaction (facial flushing) occurred in the placebo group. During the placebo phase there were three upper respiratory infections, two gastroenteritis, and one dental abscess.
Comment: The authors conclude that experimental treatment with mesenchymal stem cells was safe and well tolerated by people with relapsing MS. However, the study was very small and no other endpoints reached significance.
Stem cell therapy is an important, emerging area, and this study represents a potentially important step. The investigators followed guidelines recommended by the International Mesenchymal Stem Cell Transplantation Study Group so that their results may be compared with similarly conducted studies. Larger, longer-term, controlled studies are needed to determine the safety and potential benefits of stem cells for treating people living with MS.
The National MS 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 stem cells and MS.