Chad Swanson, PhD, Eisai Inc., describes lecanemab and summarizes investigations, both complete and ongoing, which are looking at its use in the treatment of Alzheimer’s disease (AD). Dr Swanson explains that the investigational humanized monoclonal antibody binds toxic soluble aggregated amyloid-β protofibrils and neutralizes them. The use of lecanemab was examined in a large Phase II proof of concept and dose-finding study for patients with early AD (BAN2401-G000-201; NCT01767311). A reduction in brain amyloid correlated with a reduction in clinical decline was seen following lecanemab treatment, compared with placebo-treated patients. A reduction of cerebrospinal fluid p-tau – a marker of tau pathology – was also seen compared with placebo, and lecanemab was well-tolerated. The most effective dose was determined to be 10 mg/kg biweekly, and an open-label extension (OLE) study has been initiated with this dose, which is ongoing. There are also two ongoing Phase III studies investigating lecanemab (Clarity AD; NCT03887455 and AHEAD 3-45; NCT04468659) in patients with early asymptomatic and preclinical AD respectively. This interview took place during the Alzheimer’s Association International Conference (AAIC), 2021.