MS Drug Patients Screened for Disease

About 2,000 patients who took the suspended multiple-sclerosis-fighting drug Tysabri in clinical trials have been screened for a deadly disease, but none showed signs of contracting it, the companies jointly developing the drug said Tuesday.

Elan Corp. of Dublin and Biogen Idec Inc. of Cambridge, Mass., said they were taking preliminary steps to resume clinical trials of Tysabri, which was withdrawn from the U.S. market Feb. 28 amid fears that its use could cause progressive multifocal leukoencephalopathy, or PML, a rare brain disease.

At the time, the companies said two multiple sclerosis sufferers taking Tysabri had contracted PML, one fatally. They later confirmed a second fatal case of PML in a patient using Tysabri to treat Crohn’s disease, a gastrointestinal disorder.

Elan shares rose $1.09 to $9.09 on Tuesday, and Biogen shares rose $2.82 to $41.24.

Analysts said the latest announcement signaled growing confidence by both companies that Tysabri would eventually receive renewed, if restricted, approval from the U.S. Food and Drug Administration.

“The announcement is a clear signal to patients and the FDA of the companies’ belief that Tysabri can make it back to the market,” said Ian Hunter, an analyst for Goodbody Stockbrokers in Dublin.

But other analysts cautioned that Tysabri’s potential path back to the market faced obstacles on several fronts.

The companies said they asked more than 2,000 MS patients who took Tysabri in clinical trials, mostly over a two-year period, to be screened for signs of PML. They said 91% had complied.

The screening produced no new confirmed cases of PML, the companies said.

“Given the high unmet medical need in MS and the therapeutic benefit we have seen with Tysabri, we are encouraged by these safety findings,” said Whaijen Soo, senior vice president of medical research at Biogen Idec.

Both companies said they were still screening about 1,500 people who had taken Tysabri in clinical trials for testing its effectiveness against Crohn’s disease and rheumatoid arthritis.

Another unknown is whether PML will appear in any of approximately 5,000 people, chiefly in the United States, who began taking Tysabri during the drug’s three-month availability on the U.S. market. The drug was administered every four weeks by intravenous infusion.