Alzheimer's disease: strategies for disease modification.

Alzheimer's disease is the largest unmet medical need in neurology. Current drugs improve symptoms, but do not have profound disease-modifying effects. However, in recent years, several approaches aimed at inhibiting disease progression have advanced to clinical trials. Among these, strategies targeting the production and clearance of the amyloid-beta peptide - a cardinal feature of Alzheimer's disease that is thought to be important in disease pathogenesis - are the most advanced. Approaches aimed at modulating the abnormal aggregation of tau filaments (another key feature of the disease), and those targeting metabolic dysfunction, are also being evaluated in the clinic. This article discusses recent progress with each of these strategies, with a focus on anti-amyloid strategies, highlighting the lessons learned and the challenges that remain.