The makers of Tysabri have filed new safety data and revised labeling with the FDA in a bid to reinstate the multiple sclerosis drug by next March.
Biogen Idec and Elan asked for a priority review, meaning the FDA -- if it grants the request -- would take action in six months instead of the usual 10.
"This filing...is an important step forward in our efforts to bring Tysabri back to patients in need," Amy Brockelman, Biogen Idec spokeswoman, told MM&M. "We look forward to working with regulatory authorities during the review process."
Their supplemental Biologics License Application (sBLA) for Tysabri (natalizumab) includes a safety evaluation the firms conducted, plus all available safety data from clinical trials.
No new cases of progressive multifocal leukoencephalopathy (PML)were seen in the safety assessment of 2,000 patients treated with the drug in MS trials and in data collected from the safety portion of a Crohn's and rheumatoid arthritis study.
The sBLA also comprises complete two-year data from two Phase III trials -- a monotherapy trial and an add-on trial with Avonex (Interferon beta-1a) in MS. Tysabri had been approved last year based on one-year data from those two studies.
The companies hope these data, plus a revised label and risk management plan, are sufficient to resume selling Tysabri.
The firms withdrew the drug February 28 after three cases of PML, a rare and often deadly brain disorder, showed up among clinical trial subjects. Two of these were fatal and involved patients in the add-on MS trial who had taken Tysabri and Avonex. The third involved a participant in a trial of patients with Crohn's disease.
The relationship between Tysabri and PML is not known at this time.
The revised label includes "the appropriate warnings about PML, the specifics of which will be discussed with the FDA," Brockelman said, while the risk management plan includes a patient registry.