Tysabri could be linked to new rare infections, analyst says
Withdrawn multiple sclerosis drug Tysabri may be linked to a new set of patient side effects, according to an investment bank analyst who obtained a report of adverse events connected with the drug.
Morgan Stanley analyst Steven Harr obtained a list of adverse events related to Tysabri through a Freedom of Information request, according to a report in today's Wall Street Journal.
In a note last week, Harr described that the adverse-event reports show a number of Tysabri patients died from rare infections.
"We're not trying to put a death knell on Tysabri, but there are signals in there that something's going on. It's important for patients and investors to know," Harr told The Journal.
Dismissing Harr's claims, Tysabri makers Biogen Idec and Elan told the newspaper that the companies had performed a detailed safety analysis of the drug and found no statistically significant differences between serious adverse events with patients given Tysabri and patients given a placebo in several clinical trials.
"We have an enormous amount of information in our hands," a spokesman for the companies said. "The (adverse-events) database is a limited tool."
Earlier this month, Biogen Idec and Elan said they were taking "preliminary steps" to resume clinical trials of Tysabri and that findings from their safety evaluation of the drug in patients with multiple sclerosis resulted in no new confirmed cases of progressive multifocal leukoencephalopathy (PML), a rare and deadly neurological disorder.
Biogen Idec and Elan voluntarily withdrew Tysabri from the market in February after being linked to PML.
The companies previously reported three confirmed cases of PML in Tysabri users, two of which were fatal. A total of five suspected cases of PML linked to Tysabri use have been reported to federal regulators.