Aducanumab-Related Amyloid-Related Imaging Abnormalities: Paean or Lament?

When the FDA granted accelerated approval of Biogen's Alzheimer disease drug, aducanumab (marketed as Aduhelm), it deviated from its mission of guaranteeing drug safety and efficacy because the approval was based exclusively on a perceived dose-dependent reduction in brain amyloid deposits and not upon a proven clinical effect. We believe that the amyloid-PET scans, perceived as showing decreasing amyloid deposits, are an expression of increased cerebral cell death due to aducanumab treatment, so that with time one should instead expect a worsening and not an improvement in the treated patients' condition.