Modeled Impact of APOE4 Genotype on ARIA‐E Incidence in Patients Treated With Lecanemab

Lecanemab is a humanized IgG1 monoclonal antibody that preferentially targets soluble aggregated Aβ species with activity at insoluble fibrils. A multicenter, double‐blind, placebo‐controlled phase 2 study (Study 201 Core) was conducted in 856 patients with early Alzheimer’s disease (EAD). Patients could optionally participate in an open label extension (OLE) study at a dose of 10 mg/kg bi‐weekly (Q2W). Amyloid related imaging abnormalities — edema/effusion (ARIA‐E) was a main adverse event of special interest. Incidence of ARIA‐E was lecanemab dose‐dependent and greater in APOE4 carriers. A previously presented logistic model found steady‐state Cmax was a predictor of ARIA‐E incidence and more likely in APOE4 carriers (Hussein, 2019).