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FDA: Rare brain infection linked with multiple sclerosis drug
The FDA has reported that a patient with multiple sclerosis being treated with dimethyl fumarate developed progressive multifocal leukoencephalopathy and later died.
The patient had been taking dimethyl fumarate (Tecfidera, Biogen Idec) for more than 4 years, and the manufacturer informed the FDA when the patient died after developing progressive multifocal leukoencephalopathy, or PML. The patient had a very low number of lymphocytes before developing the infection, and she was not taking any other drugs that affect the immune system or believed to be associated with PML.
PML is a rare brain infection caused by the John Cunningham virus. Although the virus is common and usually harmless, it can cause PML in patients with weakened immune systems. Symptoms of PML include progressive weakness on one side, clumsiness, vision problems, confusion and changes in thinking, personality, memory and orientation. The progression of symptoms can lead to disability and death.
This is the only confirmed case of PML reported in patients taking Tecfidera. Information about this case is being added to the Tecfidera label. The FDA advises patients taking Tecfidera to contact their health care provider if they experience PML symptoms. Providers are advised to stop Tecfidera if PML is suspected.