Researchers continually search for new or better medicines to treat multiple sclerosis (MS). MS appears to be a disease in which the immune system attacks the covering of the nerves (myelin) within the brain and spinal cord. So treatments that reduce the activity of the immune system may slow the progression of the disease. Medicines that work in this manner are called immunosuppressants. They are a major focus of MS research.
Several immunosuppressants being studied or used for MS are:
Azathioprine (Imuran), which has shown conflicting results but may reduce the number of relapses in relapsing-remitting MS.
Cladribine (Leustatin), which has been used successfully against leukemia. The U.S. Food and Drug Administration (FDA) did not approve this drug for treatment of MS because of serious side effects, including death.
Cyclophosphamide, which some experts believe stabilizes MS without improving it. But research has shown conflicting results.
Any therapy that can be used to treat MS must be judged by how it affects a person's degree of disability. Newer studies rely on the results of MRI scans and the progression of disability to evaluate how well therapy is working.