Current treatments for MS affect the entire immune system in order to prevent the autoimmune attack. While this approach can be successful at reducing disease, the suppression of normal immune function leads to side effects such as increased risk of infection and malignancy. The autoimmune attack in MS is directed against parts of the myelin proteins (peptides) contained within the sheath that insulate nerve fibres. If treatments were designed to block this specific attack, general immune system function would remain intact and side effects would be reduced.
A paper published in JAMA Neurology in July has reported the results of a clinical trial of just such a treatment, where the immune system is re-trained to start seeing myelin peptides as part of the self and prevent the autoimmune attack. Designed and implemented by a research team from the Medical University of Lodz, Poland, the treatment delivers low doses of myelin peptides through a skin patch worn on the body.
Many different components of myelin (or peptides) are under attack across individuals with MS, and identifying them has been a major goal in research. The researchers circumvented this issue by including three common MS peptides in the patch, given at two doses. 16 people with relapsing-remitting MS received low 1mg doses and 4 people received high 10mg doses over one year. These people were compared with 10 people on placebo, dummy patches which did not contain any peptides. All were assessed for active or new lesions on MRI, relapse rates and disability levels.
At the lower dose, the treatment reduced the cumulative number of active lesions on MRI by 66.5% compared with placebo. Other MRI measures of disease activity such as lesion volume and new lesions were also significantly reduced. Annualised relapse rates were reduced, with 63% of the treatment group remaining relapse free for the year compared with 10% in the placebo group. Disability scores (according to the expanded disability status scale) were significantly better on the treatment and disability progression was halted in 81% of treated patients compared with 30% untreated. The high dose did not significantly improve these outcomes and the small number of people in the high dose group were primarily assessed for safety measures.
Mild side effects of redness and itching at the site of the patch were seen in some people using the patch, although these resolved without any intervention. No serious side effects were seen. Liver and kidney tests as well as blood cell counts did not show any abnormalities.
The combination of good clinical results and lack of major side effects makes the treatment ‘an attractive and promising therapeutic approach in patients with relapsing-remitting MS’, commented the authors. We await the results of larger studies with great interest.