This is a chimeric humanized IgG1 antibody using the same sequences as the therapeutic antibody lecanemab. It binds with high affinity to amyloid-beta (Aβ) soluble protofibrils. Aβ precursor protein (APP) functions as a cell surface receptor and performs physiological functions on the surface of neurons relevant to neurite growth, neuronal adhesion and axonogenesis. Interaction between APP molecules on neighboring cells promotes synaptogenesis. The accumulation of soluble and insoluble aggregated Aβ may initiate or potentiate pathologic processes in Alzheimer’s disease. Lecanemab reduces markers of amyloid in early Alzheimer’s disease and results in moderately less decline on measures of cognition and function.