Federal regulators yesterday gave Biogen Idec Inc. good news about one of the Cambridge biotech company's key drugs.
Tysabri, a treatment for multiple sclerosis, won approval from the Food and Drug Administration to be used against another debilitating illness, Crohn's disease.
The move comes six months after an FDA advisory panel voted 12 to 3 to recommend the drug's approval to treat some forms of Crohn's, a chronic inflammatory disease of the intestinal tract. FDA officials said the final decision was delayed because Biogen Idec and Elan Corp., the Irish company that comarkets the drug, made changes to their application for a Crohn's approval.
European regulators recently rejected a similar request to use the drug as a Crohn's treatment, arguing the risk of infection outweighed the relatively modest benefit of Tysabri.
Biogen Idec temporarily shelved the drug three years ago after it was linked to a rare brain disease. The company says there have not been any additional cases of the disease since sales resumed in 2006, with new guidance on how it should be used. But some doctors remain wary of the treatment, even though it has been shown to be highly effective in some patients.
Despite the safety concerns, Biogen Idec has predicted Tysabri will eventually become a major source of revenue. This month, the company reaffirmed predictions it will be used by 100,000 patients by the end of 2010, up from more than 21,000 at the end of 2007.
Biogen Idec shares rose late in the day after the FDA news was released. The shares finished up 96 cents to $59.98, a gain of 1.6 percent.
Doctors already had permission to use the drug to treat Crohn's disease on their own, but Biogen Idec needed formal approval to start marketing the drug for that purpose.
The FDA decision does carry some caveats. Specifically, the agency approved the drug to treat patients with moderate to serious cases of the disease who can't be treated effectively with other drugs, such as steroids. The label will also carry safety warnings to reduce the risk that patients will contract the brain disease or other infections.
About 500,000 people in the United States suffer from Crohn's, but it is unclear how many of them will qualify to use Tysabri. The disease frequently causes diarrhea and abdominal cramps; symptoms can also include fever, bleeding, and weight loss. There is no cure.
Biogen Idec and Elan said they expect the drug to be available for Crohn's patients by the end of February.
Todd Wallack can be reached at twallack@globe.com.
