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www.fdanews.com/articles/75242-tysabri-screening-shows-no-new-brain-disease-cases

TYSABRI SCREENING SHOWS NO NEW BRAIN DISEASE CASES

August 10, 2005

Biogen Idec and Elan said they may restart clinical trials on their multiple sclerosis (MS) drug Tysabri after a patient safety screening revealed no new cases of a deadly brain disease that had been linked to the once promising product.

The companies are taking "preliminary steps" to resume clinical trials on the withdrawn drug in MS patients, according to a recent announcement. The companies are also conducting safety evaluations for patients who took Tysabri (natalizumab) in clinical trials for Crohn's disease and rheumatoid arthritis. Those reviews should be finished by the end of the summer, the companies said.

On Feb. 28, U.S.-based Biogen and Irish drug company Elan suspended clinical trials and withdrew Tysabri from the U.S. market after two patients contracted progressive multifocal leukoencephalopathy (PML), a rare and potentially fatal brain disease.

A third case was identified in late March. Two of the three PML victims died. At the time, analysts said the third case could effectively close the door on the drug's potential return.

The drug companies, however, said they are still investigating the possibility of a link between Tysabri and PML.

The companies said they were able to screen 91 percent of the more than 2,000 clinical trial participants for the disease. Of those patients, 99 percent had a neurological exam and 98 percent had an MRI exam.

The evaluation also included any reports of potential PML in other patients taking Tysabri. The screening found no new confirmed cases of PML.

(http://www.fdanews.com/did)