Wednesday, February 27, 2008 - 2:58 PM EST

FDA: Biogen Idec's Tysabri may harm liver

Triangle Business Journal

U.S. regulators warned Wednesday that Biogen Idec's multiple sclerosis drug Tysabri could cause liver problems in patients.

A letter posted to the Food and Drug Administration's Web site says that patients taking Tysabri, which is manufactured at a facility in Research Triangle Park, have developed signs of liver injury as soon as six days after taking their first dose.

The letter, addressed to physicians from Biogen and its Irish partner Elan Corp., says Tysabri should be discontinued in patients with jaundice or other lab evidence of liver injury. Patients also should be informed that taking the drug could harm their liver, the letter says.

In addition to its use as a treatment for multiple sclerosis, Tysabri recently won U.S. approval as a treatment for Crohn's disease, a gastrointestinal disorder. It is Biogen's fastest-growing drug, and the company hopes to have 100,000 patients taking the drug by 2011.

Tysabri was pulled from the market in 2005 after it was linked to a rare but fatal brain infection. U.S. regulators allowed it to return under a monitoring program in 2006, however, after they decided that the drug's effectiveness outweighed its risks.

Shares of Biogen Idec (Nasdaq: BIIB) were down 2.7 percent, to $59.85, in late-afternoon trading Wednesday.

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