Drug makers update effort to reinstate Tysabri
The companies said their safety review of Tysabri (natalizumab) in Crohn's disease and rheumatoid arthritis should be completed "in the coming weeks," following which they plan on submitting a supplemental Biologics License Application to the FDA for the drug in MS.
A safety evaluation of Tysabri in MS, completed in August, resulted in no new confirmed cases of progressive multifocal leukoencephalopathy (PML).
As first reported in the Associated Press, Biogen Idec CEO James Mullen said he would recommend that Tysabri's label carry warnings about three previously reported cases of PML, discovered after clinical trials, and a warning that patients with weak immune systems are more susceptible to it.
The three cases of PML, two of which were fatal, led Biogen Idec and Elan to withdraw Tysabri from the U.S. market in February and suspend clinical trials of the drug. Scientists still don't fully understand how Tysabri may have enhanced those patients' risk for contracting the rare demyelinating disease of the central nervous system.