The makers of Tysabri, a new drug used to treat multiple sclerosis, said yesterday that they are voluntarily suspending sales of the drug because one patient died and another developed a serious disease of the central nervous system.
Stocks of Biogen Idec Inc. and Elan Corp. skidded yesterday, wiping out about $17.8 billion in combined market value. Shares of the makers of rival MS drugs rose.
The biotechnology companies said in a news release that they have suspended supplying and marketing Tysabri and have advised doctors to suspend prescribing it. The companies also have stopped using the drug in clinical trials.
The companies said they decided to withdraw the drug after recent reports of two cases of serious effects among patients who used it along with an earlier Biogen Idec MS drug, Avonex, in clinical trials. One person died and another developed a suspected case of progressive multifocal leukoencephalopathy, a rare and frequently fatal disease of the central nervous system.
Both patients had taken Tysabri for more than two years in combination with Avonex, the companies said.
“Our ongoing commitment to MS patients has led us to take these steps,” said Dr. Burt Adelman, executive vice president of development at Cambridge, Mass.-based Biogen Idec. “Because we believe in the promising therapeutic benefit of Tysabri, we are working to evaluate this situation thoroughly and expeditiously. While we work through this matter, we must place patient safety above all other considerations.”
The Food and Drug Administration approved Tysabri, which was called Antegren during clinical trials, in an accelerated process after a late-stage study found that it reduced MS relapses by 66 percent compared with a placebo.
About 5,000 patients have received intravenous infusions of Tysabri since the drug’s approval in November, Biogen executives said during a conference call with industry analysts and reporters.
Elan Chief Executive Officer G. Kelly Martin said in Ireland, where the company is based, that the drug has been withdrawn as a precaution and that the companies hope to resume marketing of Tysabri later this year.
The companies said they withdrew the medication after consulting with the FDA. The agency issued a public health advisory after consulting with Biogen and Elan in the decision to withdraw the medication from the market.
Dr. Steven Galson, acting director of the FDA’s Center for Drug Evaluation and Research, said the regulatory agency “continues to believe Tysabri offers great hope to MS patients.”
“We are working with leading experts and regulatory agencies to responsibly investigate these events and to develop the appropriate path forward,” said Dr. Lars Ekman, executive vice president and president of research and development at Elan. “Our primary concern is for the safety of patients.”
Biogen’s shares plunged $28.63, or 43 percent, to close at $38.65 on the Nasdaq stock market, and Elan’s American depositary receipts, each representing one share, fell $18.90, or 70 percent, to $8. Elan slid 13.81 euros, or 68 percent, to 6.49 euros at the close of trading in Dublin.
U.S. shares of rival MS drugmaker Serono SA jumped $2.76, or nearly 18 percent, to $18.30 on the NYSE, and the American depositary receipts of Teva Pharmaceutical Industries Ltd., maker of the Copaxone MS treatment, surged $2.55, or 9.3 percent, to $30.11 in Nasdaq trading.
Tysabri was expected to be a big seller for the companies, and Elan’s shares surged in October amid published reports in Ireland that Biogen might make a friendly takeover bid for the Irish company.
Elan, once Ireland’s highest-flying company and a darling of international investors, subsequently issued a statement saying that it was not in talks with Biogen about a merger or business combination.
Tysabri, also known by the generic name natalizumab, has been designed principally to slow the progression of disabilities related to multiple sclerosis, but Elan and Biogen had previously said they thought it could also help sufferers of the gastrointestinal ailment Crohn’s disease and rheumatoid arthritis.
In December, the companies said they were starting a head-to-head study comparing Tysabri with another MS drug, Rebif. That study was to enroll 1,000 patients.
On Feb. 17, the companies announced favorable Tysabri trial results indicating success in slowing MS in patients who had relapsed, with a 42 percent reduction in the risk of a progression of the disability compared with patients who took a placebo.