Elan ( ELN) and Biogen Idec ( BIIB) said Monday morning that the Food and Drug Administration will take an additional three months to review Tysabri for treatment of Crohn's disease. The FDA will use the extra time to review the proposed risk-management plan for such a use, and the companies expect a decision by the agency on or before Jan. 13. Tysabri is already approved for relapsing forms of multiple sclerosis in the U.S. and relapsing-remitting MS in the E.U. Because two patients died in clinical studies from a central nervous system disorder (progressive multifocal leukoencephalopathy), MS patients taking the drug must register with a safety-monitoring program. Last week the company gave a safety update for that indication, saying that 17,000 patients are now taking Tysabri and no new cases of the rare and incurable nervous system disease have been reported. Elan, which has a 50% interest in Tysabri, was trading up $1.87, or 8.4%, at $24.20, while Biogen was trading up $13.64, or 19.6%, at $83.16 on
Friday's takeover talk .