Tysabri approved for Crohn's in USA

Bloomberg.com reports that the Food and Drug Administration has approved Tysabri (Natalizumab) for treating Crohn's disease in some cases. Tysabri is already being used for the treatment of Multiple Sclerosis, but was briefly withdrawn after some serious side effects. European regulators refused to approve it for Crohn's disease.

Boston.com has further information:

European regulators recently rejected a similar request to use the drug as a Crohn's treatment, arguing the risk of infection outweighed the relatively modest benefit of Tysabri.

Biogen Idec temporarily shelved the drug three years ago after it was linked to a rare brain disease. The company says there have not been any additional cases of the disease since sales resumed in 2006, with new guidance on how it should be used. But some doctors remain wary of the treatment, even though it has been shown to be highly effective in some patients.

The Wikipedia has more comprehensive background on the drug.