On February 28, 2005, biotechnology companies Biogen and Elan suspended sales of the multiple sclerosis drug Tysabri® after one patient was diagnosed and later died from the rare neurological disease progressive multifocal leukoencephalopathy, and a second was suspected of contracting it. Both patients had been using Tysabri® in combination with an earlier Biogen Idec MS drug, Avonex®.
In addition to the suspension of sales, Biogen and Elan have recommended doctors cease prescriptions immediately and have halted all marketing efforts. The decision came from both companies after consulting with the FDA.
Tysabri®, which also goes by the generic name natalizumab,
was designed to slow the progression of disabilities relating to
multiple sclerosis. Further studies showed it could also help with
the gastrointestinal ailment Chron's Disease as well as
rheumatoid arthritis.
Since the FDA approved Tysabri® in November, approximately
5,000 patients received intravenous infusions. An additional 3,000
patients received Tysabri® in clinical trials.
