According to recent estimates, about 400,000 people in the United States live with multiple sclerosis (MS). There are other conditions that are now known to be distinct from the disease but may be misdiagnosed as MS. Typically, MS can be associated with fatigue, impaired vision, problems with balance and walking, numbness or pain, tremor, and other sensory and physical changes. “With MS, the symptoms are unpredictable and vary from person to person,” explains Mark S. Freedman, MD. “Some patients may experience abnormal fatigue and episodes of numbness and tingling, whereas others lose balance and muscle coordination. All patients with MS will have unique characteristics and symptoms, making treatment challenging.”
Some drugs treat symptoms of MS whereas others modify the disease by altering the course of its progression, Dr. Freedman says. “With disease-modifying therapy, the goal is to reduce MS attacks, decrease the number of lesions seen on MRI, and slow or prevent disease progression.” Several therapies have been approved by the FDA to treat MS, some that are taken orally and others that are injected. The National Multiple Sclerosis Society recommends that patients diagnosed with relapsing MS and those whose disease is currently active consider beginning treatment with disease-modifying therapy as early as possible, as these medications lose efficacy as the disease advances.
“It can be challenging for patients to take disease-modifying medications over a long period of time,” Dr. Freedman says, “but it’s important that they understand the role of these therapies in their overall MS treatment plan.” Patients must also be made aware of the obstacles that can interfere with adherence to treatment plans. The National Multiple Sclerosis Society notes that there are many possible benefits associated with using these medications and with early treatment (Table 1).
Recently, there have been new developments in treating MS that may play an important role in patient care. For example, two new first-line oral agents—teriflunomide and dimethyl fumarate—were approved by the FDA within the past year. Many newer sphingosine 1 phosphate receptor agonists similar to fingolimod, an agent that has been on the market for a few years, are being tested with the hope of improving efficacy and safety. “Clinical trials have shown that all these agents can be effective, but it’s important to consider side-effect profiles and safety, especially over the long term, before using any therapy for MS,” says Dr. Freedman. “Because it is difficult to know which patient may respond to a particular therapy, oftentimes clinicians need to work by trial and error. The disease mechanisms may be different for each person. As such, close monitoring of treatment is paramount, both for assuring efficacy and guarding against undue side effects.”
Alemtuzumab is an injectable agent for MS that was recently approved in other countries and may be approved in the United States in the future. The drug is an attractive possibility because the dosing schedule calls for once yearly administration over 5 consecutive days the first time it is used. In clinical trials, alemtuzumab achieved good results as first-line therapy in treatment-naïve patients. The drug has been linked to higher risks for autoimmune thyroid disease and other autoimmune-mediated abnormalities, such as renal and hematologic abnormalities. As a result, it is critical for physicians to monitor patients closely and treat them swiftly for these potentially serious complications.
More research is needed with regard to the order in which therapies are used to treat MS. Other treatments in various phases of clinical trials appear to be promising, including a few monoclonal antibodies. Close monitoring of patients at higher risk of more active and progressive MS disease is also important (Table 2). Future research must determine if newer agents act differently depending on when they are used in the disease course, Dr. Freedman says. “While there is much excitement about emerging medications for MS, we still need to learn how best to use these agents during the course of therapy and when to initiate certain therapies,” he says. “We’re still learning about the mechanisms of action for these drugs. In the meantime, patients should be educated and prepared for what their treatments may accomplish. The good news is we’re expanding the tool chest to improve outcomes for this debilitating disease.”
Readings & Resources (click to view)
Freedman MS, Selchen D, Arnold DL, et al; Canadian Multiple Sclerosis Working Group. Treatment optimization in MS: Canadian MS Working Group updated recommendations. Can J Neurol Sci. 2013;40:307-323. Available at: http://cjns.metapress.com/content/84p4un8517837765/fulltext.pdf.
Coyle PK. Switching therapies in multiple sclerosis. CNS Drugs. 2013;27:239-247.
Coyle PK. The role of natalizumab in the treatment of multiple sclerosis. Am J Manag Care. 2010;16(Suppl):S164-S170.
Coyle PK. Disease-modifying agents in multiple sclerosis. Ann Indian Acad Neurol. 2009;12:273-282.
Coyle PK. Early treatment of multiple sclerosis to prevent neurologic damage. Neurology. 2008;71(Suppl 3):S3-S7.
Uitdehaag BM, Barkhof F, Coyle PK, Gardner JD, Jeffery DR, Mikol DD. The changing face of multiple sclerosis clinical trial populations. Curr Med Res Opin. 2011;27:1529-1537.
Treating Multiple Sclerosis in 2013. Medscape. November 12, 2013. Available at: http://www.medscape.com/viewarticle/813843.
Public Health Department and Statistic Brain. Available at: www.statisticbrain.com/multiple-sclerosis-statistics.