I don't know too many people that have used Tysabri to treat Crohn's, but it is back in the news again for it's lethal side effects. Business Week article is below.
Biogen Idec Inc. has reported a new case of a potentially lethal brain inflammation in a patient using its drug Tysabri, the tenth such case since the drug was reintroduced three years ago.
The company said late Friday it confirmed the presence of progressive multifocal leukoencephalopathy, or PML, on Tuesday. Biogen said the patient, who lives outside the U.S., had been using Tysabri for 30 months. Three of the ten cases of PML have been confirmed this month. In morning trading, shares of Cambridge, Mass.-based Biogen slid $2.86, or 5.7 percent, to $47.21.
Tysabri is approved as a treatment for multiple sclerosis and Crohn's disease. It was pulled from the market in 2005 due to concerns about PML, and sales resumed in July 2006 with restrictions and a monitoring program.
The ten confirmed PML cases have all been in multiple sclerosis patients, and concerns about the disease have pressured sales of the drug.
Biogen said there were about 40,000 patients on Tysabri at the end of March, with 20,800 of them in the U.S. Deutsche Bank analyst Mark Schoenebaum said in a note that the rate of PML infections in Tysabri patients is less than one in a thousand, for patients who have been on the drug for two years. He said the average time on Tysabri for the PML cases is 24 months, and that as more new infections appear, doctors may start taking patients off Tysabri sooner, or giving patients breaks from the drug.
Schoenebaum said that could "dramatically" reduce sales growth. Biogen markets Tysabri with Irish drug maker Elan Corp. PLC, whose shares dipped 38 cents, or 5.2 percent, to $6.98. Shares of PDL BioPharma Inc., which developed the drug and receives royalties on sales from Elan, declined 6 cents to $7.90.