Sales of Biogen Idec, Elan MS drug halted following death
Both companies characterized the withdrawal as a "voluntary suspension" based on recent reports of two serious adverse events that have occurred in patients treated with Tysabri in combination with Biogen's MS treatment Avonex in clinical trials. The events involve one fatal, confirmed case and one suspected case of progressive multifocal leukoencephalopathy (PML), a rare and frequently fatal disease of the central nervous system. Both patients received more than two years of Tysabri therapy in combination with Avonex.
Tysabri was approved three months ago under the FDA's accelerated process to speed the introduction of drugs for serious diseases.
Analysts had expected it to quickly become a blockbuster with annual sales of over $2 billion within a couple of years.
Tysabri's withdrawal comes at a time when pressure is mounting on the FDA to lengthen drug approval times to improve drug safety.
"This is just another black eye for the industry and another black eye for the FDA," Zacks Investment Research analyst Jason Napodano told the Associated Press. "I think we are in for a dramatic slowdown in the approval process as the FDA wants to see more extensive trials and data."