Elan Reports Mixed Alzheimer Results

There has been some hope amongst Elan and Wyeth supporters, fueled by talk from the companies themselves, that these phase II data would be strong enough to support approval of the drug. Tuesday, the companies made no mention of that accelerated approval strategy.

One of the leading theories for Alzheimer's says that sticky plaques, or clumps of protein, called beta amyloid attach to nerve cells in the brain. These beta amyloid plaques are toxic and gradually break down the nerve cells, causing the loss of cognition and function that are the hallmarks of Alzheimer's.

Bapineuzumab is an antibody that is injected into a patient. Once there, the drug is supposed to seek out and attach itself to these beta amyloid plaques; doing so allows the body's immune system to clear them from the brain.