Elan and Biogen Idec Announce TYSABRI Update Wednesday March 30, 5:21 pm ET
DUBLIN, Ireland and CAMBRIDGE, Mass.--(BUSINESS WIRE)--March 30, 2005--Elan Corporation, plc (NYSE: ELN - News) and Biogen Idec (NASDAQ: BIIB - News) announced today that their ongoing safety evaluation of TYSABRI� (natalizumab) has led to a previously diagnosed case of malignant astrocytoma being reassessed as progressive multifocal leukoencephalopathy (PML), in a patient in an open label Crohn's disease clinical trial. In light of the two previously reported cases of PML in multiple sclerosis clinical trials, Elan and Biogen Idec initiated an additional comprehensive safety evaluation of TYSABRI clinical trial patients. In the course of this safety review, the companies identified a case warranting reassessment in an open label Crohn's disease clinical trial. In July 2003, the case was reported by a clinical trial investigator as malignant astrocytoma. This diagnosis was confirmed at the time by histopathology. The patient died in December 2003.
As part of this ongoing safety review, the companies, in agreement with the clinical trial investigator, reassessed the case. Following this additional evaluation, the diagnosis is being reassessed as PML. The patient had received 8 doses of TYSABRI over an 18 month period and prior medication history included multiple courses of immunosuppressant agents.
Elan and Biogen Idec's comprehensive safety evaluation concerning TYSABRI and any possible link to PML is ongoing. The companies are reviewing clinical trial data, working with investigators to evaluate the approximately 3,000 patients in multiple sclerosis, Crohn's disease, and rheumatoid arthritis trials, and working with PML and neurology experts. The results of this safety evaluation will be discussed with regulatory agencies to determine possible re-initiation of dosing in clinical trials and future commercial availability.
On February 28, 2005, the companies announced that they had suspended marketing of TYSABRI in multiple sclerosis and dosing in all clinical trials based on two previously reported cases of PML, a rare and frequently fatal, demyelinating disease of the central nervous system