(FDA approved in bold)

• Reducing neurologic disability or relapses in patients with progressive relapsing, or worsening relapsing-remitting multiple sclerosis. (MS)
  
• Crohn’s disease (adults)

• Natalizumab is a monoclonal antibody that binds to the alpha-4 integrin chain of the very late activation antigen (VLA)-4 adhesion molecule and blocks mononuclear cell migration and costimulatory activating signals. These receptors include vascular cell adhesion molecule -1 (VCAM-1), which is expressed on activated vascular endothelium
  
• Disruption of these interactions prevents migration of leukocytes across the blood-brain barrier and reduces plaque formation as measured by MRI. It does not affect the absolute neutrophil count

• Months-years. In trials treated patients had fewer relapses up to 2 years

• Continue to use with appropriate monitoring

• For patients failing first-line agents (interferons, glatiramer) and with frequent relapses (measured by clinical outcome and MRI accumulation of lesions), consider using mitoxantrone, monthly methylprednisolone, or pulse cyclophosphamide

• Acute attacks are often treated with glucocorticoids, especially if there is functional impairment due to vision loss, weakness, or cerebellar symptoms
  
• Treat common clinical symptoms with appropriate medication for spasticity (baclofen, tizanidine), neuropathic pain, and fatigue (modafinil)
  
• The SENTINEL study showed that adding natalizumab to Interferon 1β-1a decreases clinical relapses, MRI measures of disease severity and disability compared to Interferon 1β alone, but did not compare this combination to natalizumab alone. Given that combination therapy may increase risk of adverse events, combination therapy is not recommended at this time

• Progressive multifocal leukoencephalopathy (PML) is a rare complication of treatment with natalizumab. For suspected cases, stop drug and evaluate with MRI with gadolinium and cerebrospinal fluid analysis for JC virus DNA