Natalizumab: Perspectives from the bench to bedside

Probably no other disease-modifying drug for multiple sclerosis has a more fascinating story than natalizumab from both the bench to bedside perspective and the postmarketing experience standpoint. Natalizumab is a monoclonal antibody that inhibits the trafficking of lymphocytes from the blood into the central nervous system by blocking the adhesion molecule α4-integrin. Natalizumab was approved as a disease-modifying drug for relapsing remitting multiple sclerosis only 12 years after the discovery of its target molecule—a timeline that is rather fast for drug development. However, a few months after its U.S. Food and Drug Administration approval, natalizumab was withdrawn from the market because of an unanticipated complication—progressive multifocal leukoencephalopathy. It was later reinstated with required adherence to a strict monitoring program and incorporation of mitigation strategies.