Diagnosing and Treating Multiple Sclerosis Remains a Challenge

Las Vegas—Although 2.5 million people have multiple sclerosis (MS), diagnosing MS remains difficult and treatment for the disease varies based on numerous factors. Lily Jung Henson, MD, MMM, FAAN, medical director of the neurology clinic at the Swedish Neuroscience Institute, spoke about the latest MS issues at the Fall Managed Care Forum in a session titled Managing Multiple Sclerosis: Maximizing Diagnosis and Treatment to Improve Patient Outcomes. Dr. Henson defined MS as an attack on myelin sheath orchestrated by blood-borne immune cells invading the brain through the blood-brain barrier with associated loss of neurons. Approximately 400,000 people in the United States have MS, and 200 are diagnosed each week. No single test exists for identifying MS, and the diagnosis can only be made over time and based on lesions separating. According to Dr. Henson, the introduction of magnetic resonance imaging (MRI) technology has made diagnosing MS more complicated. She cited the Barkhof criteria for diagnosing MS as indicating that a negative brain MRI does not rule out an MS diagnosis, which can only be made on clinical grounds. There are also several differential diagnoses of MS, among them lymphoma, endocarditis, Lyme disease, Cogan’s syndrome, vasculopathy, thromboembolic disorder, and central pontine myelinolysis. Dr. Henson mentioned 3 major areas of treating MS (acute attacks, disease modification, and symptom management) as well as other areas, such as health maintenance, influenza vaccines, wellness/fitness, smoking cessation, bone density, and vitamin C supplementation. In patients with acute attacks of MS, glucocorticoids or prednisone are among the drugs typically used. Dr. Henson also mentioned there are drugs and therapies available to treat several symptoms associated with MS, such as cognitive dyfunction, fatigue, depression, numbness, weakness, bowel dysfunction, bladder dysfunction, sexual dysfunction, and tremors. There are several disease-modifying therapies approved by the US Food and Drug Administration for treating MS: interferon beta-1a, interferon beta-1b, glatiramer, mitoxantrone, natalizumab, and fingolimod. Interferon beta-1a is administered as an intramuscular injection each week or as a subcutaneous injection 3 times a week in patients with relapsing remitting multiple sclerosis (RRMS). Interferon beta-1b is administered in a subcutaneous injection every other day in patients with RRMS. Potential side effects of interferon beta-1a and interferon beta-1b include influenza-like symptoms and liver and thyroid function abnormalities. Glatiramer is administered via a subcutaneous injection every other day in patients with RRMS, and its side effects may include an injection site reaction, lipoatrophy, and noncardiac chest pain. Novantrone is a cytotoxic agent administered intravenously every 3 months in patients with aggressive RRMS or secondary progressive MS. Dr. Henson said patients taking novantrone have a 1 in 400 risk of cardiotoxicity with the cumulative risk increasing with an increasing dose as well as a 1 in 135 risk of acute leukemia. Natalizumab, a humanized monoclonal antibody targeting alpha-4 integrins, is administered intravenously every 28 days in patients with RRMS who have failed another disease-modifying therapy. Dr. Henson said there had been 68 cases of patients taking natalizumab who were diagnosed with progressive multifocal leukoencephalopathy (PML), including 28 in the United States, 36 in the European Union, and 4 elsewhere. There have been 14 deaths due to PML, and 50% of the cases have had severe disability, 35% moderate disability, and 15% mild disability. Fingolimod is the first oral MS agent. Dr. Henson cited a study showing 0.5 mg of fingolimod significantly reduced the annualized relapse rate by 52% compared with interferon beta-1a (P<.001) and 1.25 mg of fingolimod significantly reduced the annualized relapse rate by 38% compared with interferon beta-1a (P<.001). Another study indicated that compared with placebo, fingolimod reduced the annualized relapse rate by 54% to 60% (P<.001), reduced MRI inflammatory activity by 74% to 85% (P<.001), reduced the risk of disability progression by 30% to 32% for 3 months (P=.02) and by 37% to 40% for 6 months (P≤.01), and reduced brain volume loss (atrophy) by 32% to 36% (P<.001).