Tysabri (Elan Pharmaceuticals and Biogen Idec)

Tysabri (Elan Pharmaceuticals and Biogen Idec) - General Information

Humanized IgG4k monoclonal antibody produced in murine myeloma cells. Tysabri (Elan Pharmaceuticals and Biogen Idec) contains human framework regions and the complementarity-determining regions of a murine antibody that binds to a4-integrin. Tysabri (Elan Pharmaceuticals and Biogen Idec) was voluntarily withdrawn from U.S. market because of risk of Progressive multifocal leukoencephalopathy (PML). It was returned to market July, 2006.

Pharmacology of Tysabri (Elan Pharmaceuticals and Biogen Idec)

In multiple sclerosis, lesions are believed to occur when activated inflammatory cells, including T-lymphocytes, cross the blood-brain barrier (BBB). Leukocyte migration across the BBB involves interaction between adhesion molecules on inflammatory cells, and their counter-receptors present on endothelial cells of the vessel wall. The clinical effect of natalizumab in multiple sclerosis may be a secondary result of its blockade of the molecular interaction of a 4b 1-integrin expressed by inflammatory cells with VCAM-1 on vascular endothelial cells, and with CS-1 and/or osteopontin expressed by parenchymal cells in the brain.

Tysabri (Elan Pharmaceuticals and Biogen Idec) for patients

If patients experience symptoms consistent with a hypersensitivity reaction (e.g., urticaria with or without associated symptoms) during or following an infusion of TYSABRI, they should report these symptoms to their physician immediately.

Laboratory Tests

TYSABRI induces increases in circulating lymphocytes, monocytes, eosinophils, basophils, and nucleated red blood cells. Observed increases persist during TYSABRI exposure, but are reversible, returning to baseline levels usually within 16 weeks after the last dose. Elevations of neutrophils are not observed.

Tysabri (Elan Pharmaceuticals and Biogen Idec) Interactions

After multiple dosing, interferon beta-1a (AVONEX 30 mcg IM once weekly) reduced TYSABRI clearance by approximately 30%. The similarity of the TYSABRI-associated adverse event profile between Study 1 (without co-administered AVONEX) and Study 2 (with co-administered AVONEX) indicates that this alteration in clearance does not necessitate reduction of the TYSABRI dose to maintain safety, General).

Results of studies in multiple sclerosis patients taking TYSABRI and concomitant interferon beta-1a (AVONEX 30 mcg IM once weekly) or glatiramer acetate were inconclusive with regard to the need for dose adjustment of the beta-interferon or glatiramer acetate.

Tysabri (Elan Pharmaceuticals and Biogen Idec) Contraindications

TYSABRI should not be administered to patients with known hypersensitivity to TYSABRI or any of its components.

Additional information about Tysabri (Elan Pharmaceuticals and Biogen Idec)

Tysabri (Elan Pharmaceuticals and Biogen Idec) Indication: For treatment of multiple sclerosis.
Mechanism Of Action: Binds to the α4-subunit of α4b 1 and α4b 7 integrins expressed on the surface of all leukocytes except neutrophils, and inhibits the α4-mediated adhesion of leukocytes to their counter-receptor(s).
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Natalizumab
Synonyms: Anti-VLA4; Anti-alpha4 integrin
Drug Category: Immunomodulatory Agents
Drug Type: Biotech; Approved

Other Brand Names containing Natalizumab: Tysabri (Elan Pharmaceuticals and Biogen Idec);
Absorption: Not Available
Toxicity (Overdose): Not Available
Protein Binding: Not Available
Biotransformation: Most likely removed by opsonization via the reticuloendothelial system when bound to leukocytes.
Half Life: 11 ± 4 days
Dosage Forms of Tysabri (Elan Pharmaceuticals and Biogen Idec): Solution Intravenous
Chemical IUPAC Name: Humanized anti a4 integrin antibody
Chemical Formula: Not Available
Natalizumab on Wikipedia: https://en.wikipedia.org/wiki/Natalizumab
Organisms Affected: Humans and other mammals