Biogen and Elan to Collaborate on Development Of Antegren^(R) (natalizumab)

Biogen, Inc. (Nasdaq: BGEN) and Elan Corporation PLC (NYSE: ELN) today   announced a worldwide, exclusive collaboration to develop, manufacture, and commercialize Antegren^(R) (natalizumab), a humanized monoclonal antibody currently nearing completion of Phase 2 clinical testing for multiple sclerosis  (MS) and Crohn's disease. Antegren represents the first of a new class of agents that has potential uses in a variety of diseases.

James C. Mullen, Biogen's President and Chief Executive Officer, said, "We see Antegren as an important opportunity for several reasons. First, it is an exciting, late-stage product with blockbuster potential in a variety of diseases.  Used alone or in combination, Antegren will allow us to offer more solutions to a broader range of MS patients than are available at the present time. And third, both Biogen and  Elan are pioneers in VLA-4 biology and the research, development, and marketing synergies between the companies should help us speed the  process of bringing this drug to patients."

Donal J. Geaney, Elan's Chairman and Chief Executive Officer, said, "We are  delighted to have concluded arrangements with Biogen to collaborate in the  development, manufacture, and eventual commercialization of Antegren. We believe that the technology and skills available from the two combined companies will be highly synergistic in the challenges of completing the development and successful introduction of this truly important product."

Antegren, discovered and developed by Elan as part of its focus on neurological diseases, is a humanized monoclonal antibody and the first in a new class of potential therapeutics known as alpha 4 integrin inhibitors that  are designed to block cell adhesion to blood vessel walls and subsequent migration of white blood cells into tissue. Antegren binds to the cell surface   receptors known as alpha-4-beta-1 (VLA-4) and alpha-4-beta-7. These  receptors are found on most types of white blood cells. Antegren may be useful in the treatment of a range of inflammatory and non-inflammatory  diseases.

Antegren demonstrated promising results in Phase 2 studies in MS reported  during 1999 and encouraging data in separate trials with Crohn's disease and ulcerative colitis patients.

18 August 2000