Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system. In people with MS, specific immune system cells (T-cells) misidentify elements of the brain and spinal cord as foreign and try to destroy them. Myelin has long been thought to be a target—the red flag to the bull—that ignites this attack process. Over the years, different strategies have been used to try to limit this immune attack. One of these is to retrain the immune system so it is tolerant to myelin. In that case, the attacking cells would simply ignore myelin and leave it alone. That is the logic underlying a recent study by Polish researchers. The goal of their study was to induce myelin tolerance and thereby reduce myelin destruction and MS attacks.
In this recent small study, researchers in Poland used a skin patch to administer small amounts (1.0 mg) of myelin particles (peptides) to 20 people with relapsing-remitting MS. In the following year, these 20 people showed significant reductions in MRI disease activity and clinical relapses when compared to ten people who were given an inactive placebo patch, and when compared to four people who received a much larger dose (10 mg).
According to Dr. Leila Jackson, Rocky Mountain MS Center immunologist and researcher, “There is a ton of work that has been done in the past on treatment of MS patients with myelin antigens—different vaccine strategies, all sorts of different things. All of the other vaccines have not been approved due to lack of efficacy or other issues. This one is exciting because they appear to have some positive results. One interesting thing about this study is that there appears to be a positive effect at the lower dose but not at the higher dose. Another is that the route of administration is different. The immune cells in the skin that would take up this antigen are completely different that those that would be targeted in an IM injection and with other vaccine strategies. They activate, and ultimately educate, different immune cells.”
The study results were positive. For those using the 1.0mg patch, the annual relapse rate was reduced by nearly 70 percent compared with the placebo group. The proportion of those with worsening disability was decreased by 51 percent. No serious adverse events were noted in the study.
This was a preliminary study involving a very small group of patients. Larger studies will need to be done to prove both safety and efficacy, but the approach is novel and the results are encouraging.