Quoted from http://www.webmd.com/multiple-sclerosis/news/20131018/fda-investigate-gilenya
FDA Investigates Brain Infection-Gilenya Case
The patient took the drug for nearly 8 months before being diagnosed with the brain infection. The FDA issued an alert at the end of August to inform the public of its investigation.
The brain infection, sometimes fatal, is called PML (progressive multifocal leukoencephalopathy). The European case is the first reported in a patient who has not previously taken the drug Tysabri (natalizumab). Tysabri is already known to be linked with a higher risk for PML.
The maker of Gilenya, Novartis, issued a statement saying it had reviewed all available evidence and that the case of PML in Europe is unlikely to be linked to the drug.
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