Shares in Biogen Idec Inc. and Elan Corp. fell sharply yesterday after a Wall Street analyst published the results of a survey suggesting doctors will be reluctant to prescribe the companies' multiple sclerosis drug, Tysabri, if the Food and Drug Administration approves its return to the market.
Deborah Knobelman, an analyst at Piper Jaffray, polled 140 neurologists in advance of an FDA meeting next week at which doctors, specialists, and patients will discuss allowing sales of Tysabri. In a note to clients, Knobelman said 59 percent of the doctors said it is too soon to bring the drug back. Only 6 percent said they would prescribe Tysabri before trying alternate treatments.
Doctors also said they would use Tysabri to treat only about 10 percent of their MS patients.
Biogen Idec shares fell $2.85, or about 6 percent, to close at $47.25. Elan shares fell $1.25, or 9 percent, to $12.70.
Biogen Idec of Cambridge and Elan of Ireland developed Tysabri together and started selling it in November 2004. Three months later, they suspended sales after two patients using it in a clinical trial contracted a rare brain disease. One of those patients died, and the company later discovered a separate case in which a patient in a trial also died of the disease. The companies have since conducted an extensive safety review that did not uncover any other cases.
Shares in the companies may also have been affected by a Bloomberg News report highlighting a scientific paper to be presented at an upcoming neurology conference that claims Tysabri can affect the immune cells of a patient in much the same way as HIV. Biogen Idec declined to comment on the study, noting that the scientific abstracts posted on the website of the American Academy of Neurology are under embargo until they are presented at the conference, which is scheduled for April 1-8.
''The article is definitely under embargo," said Robin Stinnett, a spokeswoman for the academy.
Before problems surfaced, Tysabri was expected to become a blockbuster drug generating as much as $3 billion in annual sales. Sales predictions have dropped considerably, and some analysts suggest the drug may become more of a niche treatment.
Dr. Burt Adelman, Biogen Idec executive vice president of development, said that if Tysabri sales resume, the company doesn't expect sales to grow as rapidly as when it was introduced.
''We've always said the marketplace will be cautious and there will be early adopters and there will be late adopters," Adelman said.
The FDA advisory committee considering Tysabri will meet next Tuesday and Wednesday. The panel typically votes at the end of such meetings and its recommendation is usually adopted by the agency. A decision on Tysabri's return could come later in March.
Elan yesterday said it would suspend trading in its shares during the two-day meeting.
Separately yesterday, Biogen Idec said the FDA approved its cancer drug Rituxan for use in treating patients with rheumatoid arthritis. Adelman said the drug would be used to treat the 30 to 40 percent of patients who don't respond to standard treatment, known as TNF inhibitor therapy.
''We are actively developing the drug for broader use," he said.
Jeffrey Krasner can be reached at email@example.com.