FDAnews Drug Daily Bulletin


June 7, 2006

The FDA has made the "rare" decision to allow a drug to be sold after the product was pulled from the market due to serious health concerns, despite the agency's acknowledgement that there will continue to be deaths related to the drug's use, an official said.

The FDA announced June 5 that it will allow the multiple sclerosis (MS) drug Tysabri to be marketed subject to a restricted distribution program. The announcement comes after Biogen Idec, the drug's manufacturer, voluntarily withdrew Tysabri (natalizumab) early in 2005 following two deaths associated with its use. Two patients involved in clinical trials for the drug died when they developed progressive multifocal leukoencephalopathy (PML).

Tysabri represents "one of the very rare cases" where the agency will allow a drug to return to market after withdrawal, Steven Galson, director of the Center for Drug Evaluation and Research, said in a teleconference with the media. The agency made this decision because it believes that the benefits of using the drug outweigh the 1 in 1,000 chance that patients have of contracting PML. Because MS is such a debilitating condition, the FDA made a "judgment call" to allow Tysabri back on the market, he said. The drug is used as a treatment for patients that cannot tolerate or do not respond to other MS treatments.

While the agency admitted that there "will be deaths" associated with the drug, it believes that the restrictions placed upon Tysabri's sale will limit the risks, Russell Katz, an official with the Office of Drug Evaluation I, Division of Neurology Products, said. The agency is requiring the company to apply a risk management plan for the drug.

Biogen Idec's risk management plan for the drug requires that patients using the drug be evaluated at three and six months after the first application and every six months after that. Doctors must also notify the company each time the drug is administered. Additionally, Biogen Idec must provide data to the agency from future studies of the drug. Requiring this information will allow the agency to stem any threats and assess necessary changes to the conditions of its marketing approval, Katz said. (http://www.fdanews.com/did/5_110/)