Disease Information for Natalizumab (Tysabri) Administration/Toxicity

TOXIC [2/05] Natalizumab Tysabri administration is a monoclonal bioengineered antibody that blocks exit of monocytes, macrophages, and lymphocytes from blood vessels at inflammatory sites; infusion of 300 mgm/15 ml monthly for relapsing multiple sclerosis; approved 2005; Elan pharmaceuticals; This Drug binds to monocyte/lymphomcyte cell surface alpha4 family of integrins which include vascular cell adhesion molecule (VCAM-1) also endothelial receptor (MadCAM-1); this prevents transmigration of leukocytes (not polys) into inflammed parenchymal tissue

WITHDRAWN FEBRUARY 2005 as TOXIC LINKED TO ENCEPHALOPAY, MULTIFOCAL CEREBRAL DEGENERATIVE DISORDER 2 REPORTS. fifth case report ?? june 2005:Reuters:Updated: 1:09 p.m. ET June 13, 2005 A possible fifth case of a rare and often fatal brain infection linked to the multiple sclerosis drug Tysabri has been reported to federal regulators, a Food and Drug Administration spokeswoman said Monday; The case, first reported by The Wall Street Journal earlier Monday, was submitted May 16 through the Food and Drug Administration’s Adverse Event Reporting System, which collects reports of possible drug reactions from physicians and drug makers;The drug’s makers, Biogen Idec Inc and Elan Corp. Plc , have reported three confirmed cases of progressive multifocal leukoencephalopathy, or PML, in patients taking Tysabri; Two of the patients died, and the third is reported to have shown recent improvement;

(Edit)