IDEAS becoming reality on the roadmap for biomarker validation in Alzheimer's disease

Amyloid PET has made the dream of dementia specialists come true, enabling visualisation in vivo and with high accuracy of the amyloid deposits that Alois Alzheimer described as senile plaques more than a century ago. Until recently, such visualisation could only be appreciated post mortem—far too late to be of any practical use. As is often the case, enthusiasm on this technological advancement was followed by more sobering observations. A large proportion (20–30%) of people aged 65 years and older who have intact cognitive function have a positive amyloid PET scan, making the exam more suitable to rule out than to rule in the disease (ie, a negative amyloid PET rules out Alzheimer's disease pathology as the cause of cognitive impairment, but a positive scan does not imply Alzheimer's disease pathology as the underlying factor). Additionally, amyloid is just one of two pathophysiological markers of Alzheimer's disease, the other being tau, which is more closely associated with symptom onset and for which PET tracers are emerging. In this apparently grim scenario, how can a diagnostic test of brain amyloidosis improve clinical outcomes?AMYPAD has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement number 115952. This Joint Undertaking receives the support from the European Union's Horizon 2020 research and innovation programme and European Federation of Pharmaceutical Industries and Associations. FB is supported by the National Institute for Health Research Biomedical Research Centre at University College London Hospital (UK). This publication solely reflects the author's view and neither IMI nor the European Union, and EFPIA are responsible for any use that may be made of the information contained herein