Natalizumab has been available as a multiple sclerosis treatment for more than 5 years in
Europe and the United States. Natalizumab was granted approval by the US Food and Drug
Administration in 2004, only 12 years after its molecular target was cloned. Shortly after
initial approval, natalizumab use was suspended pending a safety review when several
natalizumab recipients were diagnosed as having progressive multifocal
leukoencephalopathy. After the safety review, natalizumab was reintroduced to the market in …