Multiple Sclerosis (MS) is a chronic and progressive inflammatory neurodegenerative disease in which the body’s immune system attacks the myelin protein that insulates neuronal axons. The disease typically strikes in young adulthood and because it is progressive in nature, disability accumulates over time and can lead to permanent impairment of mobility, cognition and the ability for self-care.

According to the National Multiple Sclerosis Foundation, there are estimated to be 400,000 people with MS in the United States. More than two-thirds of MS patients are women and relapsing forms of the disease accounts for approximately 65% of MS patients. Most people are diagnosed between the ages of 20 and 50, although MS can occur in young children and significantly older adults.

Patients often exhibit an initial clinically isolated syndrome, followed by a series of subacute clinical events that spontaneously abate, referred to as relapsing remitting MS (RRMS). While patients generally return to near normal neurologic function at the cessation of each episode, over a variable period of time there can be irreversible progression of clinical disability termed secondary progressive MS (SPMS), although early therapeutic intervention may delay time to progression. However, 10%–15% of MS patients will instead experience primary progressive MS (PPMS), characterized by clinical progression from the initiation of disease without preceding relapses and remissions. About 5% of the patients show progressive disease with clear relapse exacerbations of the disease characterized as progressive relapsing multiple sclerosis (PRMS).