The Ups and Downs of Amyloid in Alzheimer's

Very recently, the Food and Drug Administration (FDA) in the United States gave an “accelerated approval” to aducanumab, the first new drug to be available to patients with Alzheimer’s disease (AD) in nearly two decades and the first ever that targets the underlying neuropathology. The accelerated approval pathway is based on a biomarker effect, in this case reduction in brain amyloid as measured by PET scan, that is “reasonably likely” to predict clinical efficacy. While there were numerous complexities surrounding the approval, this event was nevertheless seminal for the treatment of AD and for the amyloid hypothesis.