Patients who previously participated in the phase III MS trials and subsequent safety evaluation are eligible to be screened for entry in this open label multi-center study.
Sites throughout Europe, the US, Canada, Australia, New Zealand and Israel are expected to enroll patients. This safety extension study is being conducted under a FDA investigational new drug application in the US and similar investigational approvals internationally.
Biogen Idec and Elan had previously voluntarily suspended Tysabri from the US market and dosing in all ongoing clinical trials based on reports of progressive multifocal leukoencephalopathy (PML), a rare and potentially fatal, demyelinating disease of the central nervous system.
The companies completed a comprehensive safety evaluation of more than 3,000 Tysabri patients in collaboration with leading experts in PML and MS. The results of the safety evaluation yielded no new confirmed cases of PML beyond the three previously reported.
On March 8, 2006, the Peripheral and Central Nervous System Drugs Advisory Committee of the FDA voted unanimously to recommend reintroduction of Tysabri as a treatment for relapsing forms of MS.
The companies anticipate action by the FDA regarding the reintroduction of Tysabri in the US on or before June 28, 2006. The companies’ application for approval of Tysabri as a treatment for MS is also under review with the European Medicines Agency.