A new treatment for multiple sclerosis (MS) had a successful first phase of clinical trials, shows a study published in the journal Science Translational Medicine.
Multiple sclerosis is an autoimmune disease where the patient's own immune system attacks a myelin insulating layer that wraps around nerve cells. Myelin is essential for nerve cells to send messages to each other. As the myelin sheath is gradually degraded in patients with MS, over the years, they lose the ability to move. The average life expectancy for people suffering from this disease is five to ten years lower than in the rest of the population. There is currently no cure for MS and the only available treatments are immunosuppressive therapies.
In the new study, researchers from Germany, US and Austria were able to 'trick' the immune system to slow down the attack on myelin. In MS, the immune system targets myelin for destruction because it fails to recognise it as its own- basically, it thinks myelin is an invader. The aim of this research was to force the immune system to recognise and become tolerant to myelin, without compromising the ability to fight real infections. For this, the team extracted immune cells present in blood, then linked them to myelin fragments and finally injected them back into nine MS patients, along with millions of other myelin fragments.
"Our therapy only targets the auto-immune cells that are actually responsible for causing the damage in the central nervous system, but leaves the rest of the immune system alone" says Dr Stephen Miller, a research immunologist from the Feinberg School of Medicine at Northwestern University, Chicago, US. This approach may overcome the tendency to develop infections and cancer that affects patients undergoing non-specific immunosuppressive therapies to treat MS.
The team believes this therapy would be more effective in MS patients where it is well understood that their condition is highly inflammatory and mediated by auto-reactive immune responses. In more advanced stages of the disease, symptoms are not only caused by immune responses, but can also be a consequence of neurodegeneration due to permanent myelin loss.
This first phase of clinical trials was primarily to test for possible side-effects in patients receiving the new treatment. The results were positive, with no problems observed and patients reporting improvements in their condition. "We found essentially this was a safe therapy without triggering a general auto-immune attack", said Dr Miller.
"Whether it's going to be used routinely remains to be seen", he continued. "More patients have to be observed for longer periods of time to really determine if it has any effect on the disease". The team is now trying to secure funds to move on to the second phase of clinical trials to see if this method prevents the progression of multiple sclerosis in humans.
"We can't say anything about efficacy at this early stage", said Dr Reinhard Hohlfeld, from the Institute of Clinical Neuroimmunology, LMU Munich but, "based on animal models, this therapy shows great potential".