Tysabri, a multiple sclerosis drug manufactured by Elan Corporation, plc and Biogen Idec, received US Food and Drug Administration (FDA) approval for use in adult patients with moderate-to-severe Crohn's disease.

The Federal regulators approved a supplemental Biologics License Application (sBLA) of Tysabri for inducing and maintaining clinical response and remission in adult patients with moderately to severely active Crohn's disease (CD) with evidence of inflammation who have had an inadequate response to, or are unable to tolerate, conventional CD therapies and inhibitors of TNF-alpha.

Tysabri will be available for the treatment of CD upon the completion of key implementation activities related to the approved risk management plan. The companies anticipate Tysabri will be available to Crohn's patients by the end of February 2008.

"The FDA's approval of Tysabri is an important step forward in the treatment of Crohn's disease," said Dr. Stephen Hanauer, Professor of Medicine & Clinical Pharmacology & Chief of the Section of Gastroenterology at the University of Chicago Pritzker School of Medicine. "A significant number of patients either fail or cannot tolerate current therapies. The unique mechanism of action of Tysabri affords us a new class of therapy in our fight against this debilitating disease."

The FDA granted approval based on its review of Tysabri CD clinical trial data and overall safety data. The approval is accompanied by robust labelling with safety warnings; and a CD-specific risk management plan (including the mandatory TOUCH Prescribing Program) designed to inform prescribers, patients and infusion centres about the use of Tysabri and to minimize potential risk of progressive multifocal leukoencephalopathy (PML) and other opportunistic infections.

"We are delighted that Tysabri will be available for Crohn's patients and their physicians, who continue to need new therapeutic options with novel mechanisms of action," said Gordon Francis, MD, senior vice president, Global Clinical Development, Elan. "We are committed to providing therapeutic choice to those patients who can benefit from Tysabri, and will continue to work with the FDA and the medical community to implement the TOUCH Prescribing Program for Crohn's patients."

The TOUCH (Tysabri Outreach: Unified Commitment to Health) Prescribing Program was developed in conjunction with the FDA to facilitate appropriate use of Tysabri and to assess, on an ongoing basis, the incidence and risk factors for PML and other serious opportunistic infections associated with Tysabri treatment. The program already has been implemented for patients receiving Tysabri therapy for MS.

An estimated 500,000 people in the United States have Crohn's disease, a chronic and progressive inflammatory disease of the gastrointestinal tract, which commonly affects both men and women.

Tysabri increases the risk of progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the brain that usually leads to death or severe disability. Other serious adverse events that have occurred in Tysabri-treated patients included hypersensitivity reactions (e.g., anaphylaxis) and infections.

Tysabri has previously been approved for relapsing forms of MS in the United States and relapsing-remitting MS in the European Union. According to data that have been published in the New England Journal of Medicine, after two years, Tysabri treatment led to a 68 per cent relative reduction (p<0.001) in the annualised relapse rate compared to placebo and reduced the relative risk of disability progression by 42-54 per cent (p<0.001). In addition to the United States and European Union, Tysabri is also approved for MS in Switzerland, Canada, Australia, New Zealand and Israel. Tysabri was discovered by Elan and is co-developed with Biogen Idec.

Elan Corporation, plc is a neuroscience-based biotechnology company committed to making a difference in the lives of patients and their families by dedicating itself to bringing innovations in science to fill significant unmet medical needs that continue to exist around the world.

Biogen Idec creates new standards of care in therapeutic areas with high unmet medical needs. Founded in 1978, Biogen Idec is a global leader in the discovery, development, manufacturing, and commercialisation of innovative therapies.