The filing is based on the results of three trials of Tysabri assessing the safety and efficacy as both an induction and maintenance therapy. The filing also includes proposed labeling and a risk management plan, both of which are similar to those approved for the multiple sclerosis indication.
Tysabri was suspended in 2005 as a multiple sclerosis treatment it was linked to a rare brain disease called progressive multifocal leukoencephalopathy (PML). Because of the increased risk of PML, Tysabri is generally recommended for patients who have had an inadequate response to, or are unable to tolerate, alternate multiple sclerosis therapies.