Biogen Idec says sixth patient has brain disease
Biogen Idec Inc. said a patient taking its multiple sclerosis drug Tysabri was diagnosed with a life-threatening brain illness, the sixth case reported since July.
The patient, who has MS, was confirmed to have progressive multifocal leukoencephalopathy, or PML, on Wednesday and had been taking the drug for 31 months, according to a report on Cambridge-based Biogen Idec's website. The patient lives outside the United States, according to the report.
Biogen Idec and marketing partner Elan Corp. pulled Tysabri from the market in 2005 after three patients, two of whom died, developed the brain infection. The Food and Drug Administration allowed sales to resume in July 2006 after deciding benefits for slowing MS relapses outweighed the risk. There were no reported infections for about two years after the drug's reintroduction.
More details on this case and others will be provided at medical meetings, said Shannon Altimari, a spokeswoman for Biogen Idec.
As of the end of March, about 40,000 patients worldwide were on Tysabri, and about 56,700 patients have used the drug, according to Biogen Idec. The likelihood of getting PML from Tysabri is about 1 in 1,000, according to the drug's label.