FDA updates label on Tysabri to note risk of brain infection
February 9th, 2010 joshua
The Food and Drug Administration has updated the warning labels on Biogen’s multiple sclerosis drug Tysabri, noting the risk of developing a rare brain infection.
Labels of the drug will now contain information about the possible risk of progressive multifocal leukoencephalopathy (PML). Since 2006, the FDA has documented at least 31 cases of the brain infection among patients on Tysabri. Eight of those patients have died as a result of the infection.
Tysabri is prescribed to MS patients to reduce the symptoms of the disease, and in updating the label, the FDA said it still believes the benefits outweigh the risks to taking it. It was pulled from the market for two years after initial reports of PML surfaced.
The chance of developing PML after beginning a course of Tysabri is 1 in 1,000.
