Tysabri's 'Diminished Future Sales Potential'

Credit Suisse First Boston maintained a "neutral" rating for Biogen Idec after news reports claimed a fourth patient taking Tysabri contracted the potentially fatal brain disease PML. The Boston Globe reported that Biogen Idec informed the Food and Drug Administration that a patient may have contracted the rare brain disease after taking the multiple sclerosis drug pulled by Biogen Idec and partner Elan last February.

Forbes (http://www.forbes.com/business/healthcare/2005/06/02/0602automarketscan20.html)