BOSTON (Reuters) - Biogen Idec Inc. said on Thursday that there have been no new confirmed cases of a potentially fatal brain infection associated with its multiple sclerosis drug Tysabri, generically known as natalizumab
Data presented at the annual meeting of the American Academy of Neurology showed no new confirmed cases of progressive multifocal leukoencephalopathy, or PML, a rare and potentially deadly brain disease, since the drug was reintroduced to the market last July.
Tysabri, developed with Biogen's partner Elan, was taken off the market in 2005 after being linked with three cases of the infection. The U.S. Food and Drug Administration allowed the drug back because it is effective and patients asked for it to be returned.
"It's comforting to see that there are no new cases or PML or other opportunistic infections," said Eric Schmidt, an analyst at Cowen & Co. "But the experience is not long enough to change the way physicians are thinking about this product."
Many doctors are likely to wait one or two years before prescribing the drug, which is currently taken by about 10,000 people worldwide, Schmidt said.
Tysabri is available in the United States through a safety-monitoring program known as TOUCH. All prescribers, infusion sites and patients are required to enroll in the program which is designed monitor patients for any signs and
