Natalizumab

Natalizumab is a recombinant humanized IgG4κ monoclonal antibody that binds to α4-integrin. While natalizumab was originally approved by the FDA to treat multiple sclerosis in 2004, it was withdrawn from the market following multiple reports of fatal progressive multifocal leukoencephalopathy (PML). In 2006, the FDA reintroduced the drug to the market for multiple sclerosis. Natalizumab was further approved by the FDA for the treatment of Crohn's Disease in January 2008.

On August 24, 2023, the first biosimilar to natalizumab, natalizumab-sztn, was approved by the FDA.

Natalizumab is indicated as monotherapy for the treatment of relapsing forms of multiple sclerosis, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease in adults.

It is also indicated for inducing and maintaining clinical response and remission in adult patients with moderately to severely active Crohn’s disease with evidence of inflammation who have had an inadequate response to or are unable to tolerate, conventional therapies and inhibitors of TNF-α. It is not to be used in combination with immunosuppressants or inhibitors of TNF-α.