The World Awaits: First AD Vaccine Nears Human Testing

Summary of the presentation made by Dale Schenk, PhD, Elan Pharmaceuticals, San Francisco, California, USA.

One of the more exciting presentations at the World Alzheimer Congress in July of this year was that of Dr. Schenk from Elan Pharmaceuticals who discussed the effort of his research group to develop a possible vaccine for Alzheimer's disease (AD).

Dr. Schenk began his lecture with a discussion of the mechanism of A-Beta (Ab) peptide production and metabolism. The Ab peptide is cleaved from the brain by proteolysis and can form b-amyloid tangles in the brain, which are associated with neuropathology and cognitive dysfunction. These neurofibrillary tangles then form amyloid plaques which are hypothesized to impede nerve cell function and cause nerve cell death in the brains of most individuals with Alzheimer's disease. Dr. Schenk's research addressed the question of whether the balance between normal proteolysis and tangle formation can be switched in affected patients. The Ab plaques appear to result from astrocytosis (an age-dependent phenomenon) at the level of the neuritic plaque. A synthetic form of the b-amyloid protein, AN1792, was injected into young mice and found to prevent AD by significantly decreasing amyloid deposition and astrocytosis in these mice at the time of their assessment at 13 months of age (mid-life for a mouse). It appeared, then, that the injection of AN1792 could stop disease from developing in the first place.