Natalizumab’s mechanism of action

Natalizumab is a monoclonal antibody that binds to alpha-4 integrin receptors on vascular endothelial cells. Integrins are a class of selective adhesion molecules composed of multiple subunits that, as a class, contribute to the chemotaxis of leukocytes to sites of systemic inflammation. Natalizumab reduces inflammation by adhering to receptors that bind to these integrins during an inflammatory episode, directly preventing white blood cells from traveling through blood vessels and producing a pro-inflammatory response. In patients with multiple sclerosis, natalizumab blocks the α4-β1 integrin receptor in the blood-brain barrier, thereby preventing white blood cells from entering the patient's central nervous system (CNS).