About Multiple Sclerosis^1,2

Multiple sclerosis (MS) is a potentially disabling disease of the brain and spinal cord, affecting 400,000 people in the U.S. and 2.1 million people worldwide. It occurs as a result of the immune system attacking the protective sheath (myelin) that covers nerve fibers, resulting in communication problems between the brain and the rest of the body. Eventually, the disease can cause permanent damage or deterioration of the nerves. 

Signs and symptoms of MS vary widely and depend on the amount of nerve damage and the specific nerves are affected. Common symptoms include numbness or weakness in one or more limbs, electric-shock sensations with certain neck movements, tremor, lack of coordination, or unsteady gait. Some people with severe MS may lose the ability to walk independently or at all, while others may experience long periods of remission without any new symptoms. Vison problems are also common in patients with MS, including partial or complete loss of vision, usually in one eye at a time, prolonged double vision, or blurry vision.  Other symptoms may include slurred speech, fatigue, dizziness, and tingling or pain in parts of the body. Significant disability occurs within 20-25 years in greater than 30% of patients.

Most patients (85%) have relapsing-remitting MS, experiencing periods of new symptoms or relapses that develop over days or weeks and usually improve partially or completely. These relapses are followed by quiet periods of disease remission that can last months or even years. About 60 to 70 percent of people with relapsing-remitting MS eventually develop a steady progression of symptoms, with or without periods of remission, known as secondary-progressive MS. Some people with MS experience a gradual onset and steady progression of signs and symptoms without any relapses. This is known as primary-progressive MS. 

Treatment of MS includes immunomodulatory therapy (IMT) to address the underlying immune disorder and therapies to relieve or modify symptoms. The goal of IMT is to reduce the frequency of relapses and slow disease progression. Although there are numerous disease-modifying agents on the market, most have been approved for use only in relapsing forms of MS. There is a significant need for drugs that are effective in treating progressive MS.