Yednock relates the discovery and development, over 15 years, of the drug Tysabri, an alpha4 integrin antibody, as a treatment for multiple sclerosis.



In the first of his two talks, Ted Yednock begins with an overview of multiple sclerosis.  He describes how, in MS, immune cells are able to transverse the wall of blood vessels and infiltrate the brain and central nervous system resulting in damage to the myelin surrounding neurons.  Yednock and his colleagues hypothesized that by blocking the infiltration of immune cells into the brain, the progression of the disease might be slowed.  They went on to identify alpha4 integrin as the molecule that mediates adhesion of immune cells to the blood vessel wall, and they found that an alpha4 integrin antibody (Natalizumab or Tysabri) could block infiltration of the blood cells into the brain in a animal model of MS.  Yednock then details the clinical development of Tysabri through to its approval by the FDA in 2004.