Tysabri (natalizumab) is a monoclonal antibody that affects the actions of the body's immune system. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage.
Tysabri is used to treat relapsing forms of multiple sclerosis in adults (including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease).
Tysabri is also used to treat moderate to severe Crohn's disease in adults. It is usually given after other medicines did not work or have stopped working.
