Multiple Sclerosis Drug Tysabri Showed Promise - MS Sufferers Ask the Food and Drug Administration to Bring it Back to Market

March 2nd 2006

Tysabri

Stanford researchers have found that the new drug natalizumab (Tysabri) can have fatal consequences. The drug went through the U.S. Food and Drug Administration (FDA) fast-track approval process in 2004 following promising results seen early in two clinical trials. The drug has been used to treat multiple sclerosis (MS).

Two patients have contracted a rare brain infection called progressive multifocal leukoencephalopathy (PML) last month, and two died of the disease. This spurred the marketer, Biogen Idec and Elan Pharmaceuticals, to pull the drug off the market until the risks can be investigated.

Multiple sclerosis is an immune disorder that affects 400,000 Americans, mostly young adults. MS is a debilitating disease that begins with numbness and muscle weakness, often getting worse with time. The disease will cause nervous system damage.

Multiple sclerosis can lead to a loss of motor control and possible paralysis. MS damages the nerve cells by attacking their myelin protective sheath. The current medications are not always effective in treating MS. Tysabri has been shown to alleviate the symptoms.

After the first year of the two-year clinical trials, Tysabri appeared to block the disease effects, and did not seem to cause any more infections. There were two deaths associated with the drug’s use.

The study in the Lancet includes the case of Anita Louise Smith, who enrolled in the experimental drug trial in 2002 in Colorado. She had been newly diagnosed with MS and was hoping to reduce the future symptoms associated with the disease. Last year, she died at the age of 46 from the PML infection linked to the drug.

The deaths prompted two Stanford University School of Medicine neurologists, Langer-Gould MD and Lawrence Steinman MD, to evaluate the appropriateness of testing the drug on people with no evidence of the disease. According to the Lancet article, the two are concerned about testing a drug on people who are not yet disabled at the time of the trial. "We are arguing that people with no disability should probably not enter into a clinical trial or be recruited into clinical trials, because where is the potential benefit to them if nothing is wrong?" said Steinman.

Many consider the risk low and now there is a call for bringing Tysabri back to market. According to ABC News, Tysabri is a "significant advance" for MS patients, said Dr. Allan H. Ropper, author of an editorial that accompanied the studies published in The New England Journal of Medicine. He is chairman of the department of neurology at Caritas St. Elizabeth's Medical Center and chairman and professor of neurology at Tufts New England Medical Center in Boston.