Impact of amyloid imaging on drug development in Alzheimer's disease

Imaging agents capable of assessing amyloid-beta (A) content in vivo in the brains of Alzheimer's disease (AD) subjects likely will be important as diagnostic agents to detect A plaques in the brain as well as to help test the amyloid cascade hypothesis of AD and as an aid to assess the efficacy of anti-amyloid therapeutics currently under development and in clinical trials. Positron emission tomography (PET) imaging studies of amyloid deposition in human subjects with several A imaging agents are currently underway. We reported the first PET studies of the carbon 11-labeled thioflavin-T derivative Pittsburgh Compound B in 2004, and this work has subsequently been extended to include a variety of subject groups, including AD patients, mild cognitive impairment patients and healthy controls. The ability to quantify regional A plaque load in the brains of living human subjects has provided a means to begin to apply this technology as a diagnostic agent to detect regional concentrations of A plaques and as a surrogate marker of therapeutic efficacy in anti-amyloid drug trials. (C) 2007 Elsevier Inc. All rights reserved.