Biogen Idec and Elan have restarted a safety extension study of multiple sclerosis treatment Tysabri. The companies previously suspended dosing in all ongoing trials of the drug after it was linked with a potentially fatal side effect.
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 multicenter study. Sites throughout Europe, the U.S., 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 U.S. and similar investigational approvals internationally.