
That changed on Aug. 28 of last year when Yout, 45, was diagnosed with a rare brain infection that developed as a side effect of Tysabri, a drug she took for six years to keep her MS in check. Yout’s speech became slurred, her gait unsteady, and her future uncertain. “I was a very successful businesswoman,” said Yout, who lives in Hanover. “Today, I can’t even balance my checkbook, I can’t use an ATM, I can’t see out of one eye. I had to move back in with my mother. I’ve lost my independence. I’ve lost everything.” Now, she is suing the two companies that marketed Tysabri — Biogen Idec Inc. of Weston and the Irish drug maker Elan Pharmaceuticals Inc.
The lawsuit is one of at least a half-dozen pending in Massachusetts and federal courts in three other states. In each case, plaintiffs are seeking more than $1 million in punitive damages from Biogen Idec and Elan on behalf of patients or their families. After taking Tysabri, the patients developed progressive multifocal leukoencephalopathy, known as PML, an infection of the brain’s white matter that can cause death or severe disability. Her complaint, filed Friday, alleges they failed to adequately warn patients of the risks some face from prolonged use of Tysabri.more