Breakthrough Therapy Approved for Alzheimer Disease 

Through its Accelerated Approval Pathway, the Food and Drug Administration (FDA) approved lecanemab-irmb (Lequembi; Eisai, Tokyo, Japan; and Biogen, Cambridge MA) to treat patients with Alzheimer disease (AD). The approval is based on data that show a reduction in amyloid-beta (Aβ) plaques visualized in PET scans and slower cognitive decline in those taking lecanemab compared with those taking a placebo. 

Researchers conducted an 18-month, multicenter, double-blind phase 3 trial involving individuals aged 50 to 90 years diagnosed with early forms of AD (mild cognitive impairment or mild dementia) who had evidence of Aβ plaques. Participants were assigned to receive either lecanemab as an intravenous infusion (10 mg/kg) once every 2 weeks or a placebo. In all, 1795 participants were enrolled, with 898 assigned to receive lecanemab and 897 in the placebo group. Individuals taking lecanemab showed less cognitive decline over time according to the Clinical Dementia Rating–Sum of Boxes test compared with those taking a placebo. A substudy analysis involving 698 participants demonstrated a greater reduction of Aβ plaque burden on composite PET scans in those taking lecanemab compared with others. 

“The approval of Lequembi provides new hope to patients with Alzheimer’s disease,” said Christopher A. Viehbacher, President and Chief Executive Officer, Biogen. “Patients at an early stage of the disease and their caregivers can now consider a new treatment option with their doctors.” 

Lecanemab is a humanized immunoglobulin gamma 1 (lgG1) monoclonal antibody directed against aggregated soluble (“protofibril”) and insoluble forms of amyloid beta for the treatment of AD. The most common adverse reactions reported were infusion-related reactions, headache, cough, and diarrhea.