Continued Discussion of the Ability of Immunotherapies to Remove Amyloid- β from the Brain

Is amyloid-β aggregation an important cause of Alzheimer's disease, or is it a side-effect of other, more important mechanisms? Near all age-related conditions are complex, with multiple interacting mechanisms involved. Absent a way to remove just one of those mechanisms, it is quite hard to say which are more or less important. In Alzheimer's disease this is made worse by the fact that the animal models are very artificial: few shorter lived mammals naturally develop anything even remotely resembling the biochemistry of Alzheimer's disease. Thus whether or not a treatment produces benefits in animal models is a poor indicator of whether or not it will produce benefits in humans. The quality of the model rests on unproven assumptions about the relevance of specific mechanisms to the condition. There are now several approaches shown to be capable of removing a large fraction of amyloid-β from the brains of human patients, after many years of slow and painful development. The evidence from human trials shows that benefits to cognitive function and disease progression are muted at best, and more likely absent. This is unfortunate, but we can't expect every choice of target to be a success. The poor outcomes of trials of anti-amyloid immunotherapies strongly suggest that amyloid-β is not an important mechanism in Alzheimer's disease, or at least if it is, then this is the case only during the early, slow development of the condition, setting the stage for immune ...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs