Tysabri has been in the news again this week.  Last Friday the European Medicines Agency (EMEA) announced that they would review the benefits and risks for Tysabri.

The Committee started a review of the benefits and risks of Tysabri, in view of reports of 23 cases of progressive multifocal leukoencephalopathy (PML) worldwide since Tysabri has been on the market. This review is initiated to discuss any additional measures necessary to ensure the safe use of Tysabri and how to balance the risks to the patients against the benefits of the treatment. Tysabri is indicated for patients suffering from highly active relapsing remitting multiple sclerosis with high disease activity despite treatment with a beta-interferon and for patients with rapidly evolving severe relapsing-remitting multiple sclerosis.

This information hit the stock market on Friday, affecting the stock prices of Elan (ELN) and Biogen Idec (BIIB).  Then it was spread by various news channels and MS organizations on Monday.  Drowned in the minor uproar was an announcement that a 24th patient had developed progressive multifocal leukoencephalopathy following Tysabri use which was reported to EMEA on Sunday. 

Interestingly on Tuesday, articles started coming out which either blamed European doctors on the increase in PML cases or touted a revival strategy for the use of Tysabri involving a test for the JC Virus which causes PML.  And to cap off the news alerts and search engine results for folks looking for recent news regarding Tysabri, Elan and Biogen choose this time to announce that Tysabri use in Crohn's Disease cuts hospitalization rates.

Last week before this latest round of announcements and articles appeared, Tysabri was discussed at length during a conference call conducted by Biogen Idec.  Here's an excerpt from the Motley Fool article - All Tysabri, All the Time.

Increasing the number of patients on the drug may only get harder, though. On the conference call, management said that Elan and Biogen now believe that the risk of developing progressive multifocal leukoencephalopathy (PML), a potentially deadly brain infection, increases with the number of infusions a patient receives. Biogen is in discussions with the Food and Drug Administration to update the label to reflect this new belief.

The change could result in patients taking breaks from Tysabri, perhaps going onto other medications and then returning later. Just realize that drug holidays for patients result in revenue holidays for Biogen and Elan, so they're definitely not a reason to celebrate with friends and families.

Also on Friday, Bloomgberg reports that the Food and Drug Administration (FDA) confirmed the number of PML cases.  Note that as of Sunday, this information is already somewhat out-of-date with the report of the 24th case of the (potentially lethal) brain infection.  Here is an exerpt from Biogen, Elan Fall as Tysabri Brain Disease Cases Rise.