At a glance:
This is an abstract of an article from the New England Journal of Medecine, which examines the risk of developing progressive multifocal leukoencephalopathy (PML)in patients taking the drug natalizumab.
The drug is used in the treatment of multiple sclerosis, Crohn's Disease and rheumatoid arthritis and has been linked with the development of the rare brain disease PML in some patients.
This particular study did not detect any further cases of PML in the group of over 3000 patients tested.