Quoted from http://www.reuters.com/article/rbssHealthcareNews/idUSN2448723320090724
Biogen reports 11th Tysabri brain infection case
Fri Jul 24, 2009 11:00pm EDT
BOSTON, July 24 (Reuters) - An 11th patient taking Biogen Idec Inc's multiple sclerosis drug Tysabri has developed a potentially deadly brain infection since July 2006, when it was reintroduced to the market.
The Cambridge, Massachusetts-based biotech company released the news on its website late on Friday.
Tysabri, which Biogen sells in conjunction with Irish drugmaker Elan Corp Plc , is considered critical to the future growth of both companies.
The drug was temporarily withdrawn from the market in 2005 after it was linked with a brain infection known as progressive multifocal leukoencephalopathy, or PML. It was brought back in 2006 with stricter safety warnings.