Replies to post #83367 on Biotech Values

[DewDiligence]

BIIB reports two more cases of Tysabri PML (#69 and #70 overall):

http://www.reuters.com/article/idCNN2024384420101020

20% of the 70 confirmed PML cases have been fatal.

For patients who have been on therapy for at least two years, the PML incidence has been 1 case in every 535 patients.