What’s Happening in MS Research? A HealthCentral Explainer
Research in multiple sclerosis is progressing at an unprecedented rate, with more potential treatments and therapies being developed than ever before.
Given the complexity of multiple sclerosis (MS)—a chronic disease that attacks the central nervous system—research of the condition is typically an effort involving multiple stages, including early discovery research, translational research, clinical trials, drug repurposing and health policy research.
According to the National Multiple Sclerosis Society (NMSS), the three big areas of research include disease-modifying therapies, environmental factors, and the role of genetics.
Disease-modifying therapies (DMTs)
Disease-modifying therapies are a relatively new treatment method, developed over the past 20 years. DMTs can be categorized as oral drugs, self-injectables or infusible medications, and they have become an accepted part of MS treatment. The medications have proven successful in reducing the frequency of exacerbations and slowing down the progression of a person’s disabilities.
Researchers recently have been paying more attention to the need for DMTs that can treat progressive forms of MS, including primary-progressive MS (PPMS), since the 10 currently available FDA-approved DMTs have been proven only to be effective in relapsing forms of MS, including relapsing-remitting MS (RRMS), secondary-progressive MS (SPMS) and progressive-relapsing MS (PRMS). Some studies have demonstrated a minor reduction in relapse rate in patients with progressive MS. There is not sufficient evidence, however, that DMTs are an effective treatment for PPMS patients.
The challenge of treating progressive MS with DMTs stems in part from the differences between primary-progressive MS (PPMS) and other types of the condition. For example, PPMS involves less inflammation than is commonly seen in relapsing MS, which results in people with PPMS having brain lesions containing relatively few inflammatory cells. Lesions in people with PPMS tend to be more prevalent in the spinal cord than in the brain. PPMS affects approximately 10 percent of MS patients when first diagnosed, while RRMS affects approximately 85 percent.
Scientists have not ruled out the possibility of treating progressive forms of MS, since the majority of DMTs target inflammation and there is some--although relatively little--inflammation in people with PPMS. Past and current trials of DMTs specifically for people with PPMS are slowly leading to the possible development of new treatments. Researchers have been testing the effects of fingolimoid tablets, for example, on PPMS patients since 2009 and are currently evaluating whether they are effective at delaying disability progression.
Other recent studies have examined the effects of environmental factors, such as vitamin D and exercise, on MS symptoms.
Vitamin D supplements may help improve long-term memory in people with MS, according to a recent study published in Cognitive and Behavioral Neurology. In this study, researchers looked at the correlation between cognitive functions in people with RRMS and vitamin D levels. Findings showed that people with higher vitamin D levels demonstrated better long-term memory.
A recent clinical trial conducted on mice, whose report was published in the Proceedings of the National Academy of Sciences, found that vitamin D can block damage-causing immune cells from entering the central nervous system. When researchers gave mice the rodent form of MS and a high dose of vitamin D, they found that the vitamin helped protect the mice from developing symptoms of MS. The scientists concluded that vitamin D may be an effective and safe treatment for MS, but additional studies are needed to determine if vitamin D can have the same effect in humans.
Another growing body of research supports the belief that people with multiple sclerosis can benefit from exercise. Evidence has shown that exercise can help combat some MS symptoms by improving endurance and stamina, cognitive function, fatigue and psychological health. One recent study, published in The Neural Basis of Cognition, found the first evidence for the beneficial effects of aerobic exercise on the brain and memory in people with MS. This finding offers a promising treatment opportunity for the approximate 50 percent of people with MS with memory deficits, for which there are not yet effective pharmacological treatments. Evidence has also shown that exercise therapy may help reduce fatigue in people with MS, but relatively few studies have specifically examined the effects of exercise on fatigue.
The role of genetics
Scientists do not know what exactly causes MS, but various factors are believed to contribute to the onset of the disease.
Among those factors is genetics. According to the National Multiple Sclerosis Society, people may be born with a genetic predisposition to MS, increasing a person’s risk for reacting to certain environmental agents that can trigger an autoimmune response. Evidence has not concluded that MS is hereditary, but studies have shown that having relatives with MS increases a person’s risk for developing the disease.
The most recent report on the role of genetics in MS, published in 2013 in the journal Nature Genetics, identified 48 new genetic variants associated with MS risk. The study brings the current total number of known genetic risk factors for MS to 110. Researchers analyzed DNA from almost 30,000 people with MS and approximately 50,000 people without MS. Their findings, in addition to identifying new genetic variants, confirmed previous evidence of genetic factors connected to MS risk.
Scientists hope that by better understanding the role of genetics in MS, they can develop new therapies to help prevent it from developing in people with a genetic predisposition for MS. Researchers said they plan to conduct a second large-scale study to confirm the role of the 48 newly-discovered genes.
Other areas of MS research
According to Dr. Timothy Coetzee at the NMSS, other big areas of research on MS includes the following:
- Rehabilitation medicine and rehab programs: Common rehabilitation programs for MS include physical therapy, occupational therapy, cognitive rehabilitation, vocational rehabilitation and speech-language pathology. Rehabilitation specialists often work with MS patients to help maximize physical abilities, maintain functionality at work and at home and increase patient safety and independence.
- How and why MS affects the immune and nervous system: The weight of evidence shows that MS is an immune-mediated disease, which means that MS causes the body’s immune system to attack healthy nerve tissue, which can then cause nerve damage throughout the body. Researchers continue to investigate how certain treatments and medications can suppress the immune system and slow the progression of MS.