The law firm Schatz & Nobel, P.C. announced Thursday that it has filed a lawsuit against Biogen Idec Inc. on behalf of all persons who purchased securities of Biogen between February 18, 2004 and February 25, 2005, (the “Class Period”).

The lawsuit alleges that Biogen violated federal securities laws by issuing false and misleading information about its multiple sclerosis drug Tysabri. Specifically, the lawsuit accuses Biogen of failing to disclose that Tysabri can increase the risk of progressive multifocal leukoencephalopathy.

PML is a rare, serious progressive neurologic disease usually occurring in immunosuppressed patients. There is no known effective treatment for PML. Although the relationship between Tysabri and PML is not known at this time, because of the serious and often fatal nature of PML, FDA concurred with the company that the drug be voluntarily withdrawn from marketing and that the use of Tysabri in clinical trials be suspended until more is known.

On this news, the complaint contends that shares of Biogen fell $28.63 per share, or 42.44%, to close at $38.65 per share.

In addition, the lawsuit accuses Biogen of concealing “these facts” in order to fast track Tysabri for FDA approval so “they” could reap the finacial benefits from the sales of the Tysabri.

The suit was filed in the U.S District Court for the District of Massachusetts.

(via PR Newswire)