Disease Modifying Drugs in Multiple Sclerosis: Mechanisms of Action and New Drugs in the Horizon

The term "disease modifying drugs" (DMD) is taken from rheumatologists who coined it after the use of immunosuppressive drugs and, more recently, the association of "biological drugs" that changed the degenerative course of rheumatic disease. In the treatment of multiple sclerosis (MS), the advent of interferon (IFN)-beta, which caused a reduction in the number of relapses and possibly improvement in disability outcomes, was the first strategy to prevent inflammatory damage in the central nervous system (CNS). Soon after, glatiramer acetate showed similar results. It would be more than a decade before natalizumab was licensed, showing a much better efficiency in relapse reduction than was seen after first-line therapies failed. The pipeline is now much larger with several drugs on the horizon. Overall, the anti-inflammatory strategy has been mostly successful but drugs that have protection and repair mechanisms are still missing.