Detour in attack on MS
It is not intuitively obvious why a treatment should work for chronic multiple sclerosis, but not for acute therapy. But that is what Elan Corp. plc hopes will be the case, after the company announced last week that its Antegren (natalizumaba) anti-a4 integrin antibody failed to show efficacy in a Phase II acute therapy trial. The company now will only pursue chronic treatment of MS after the disease progression shown in the human trials did not follow the preclinical mouse models.
Binding of Antegren to a4 integrin blocks the interaction of the cell adhesion molecule on leukocytes with its counter receptor found on endothelial cells, vascular cell adhesion molecule-1 (VCAM-1). With the VCAM-1 receptor blocked, endothelial cells in the brain are unable to take up leukocytes, preventing inflammation and subsequent tissue damage. ...