The FDA Grants Full Approval for Leqembi for the Treatment of Alzheimer Disease

The Food and Drug Administration (FDA) has granted traditional approval to Leqembi (lecanemab-irmb; Eisai, Tokyo, Japan; Biogen, Cambridge, MA) for the treatment of people with Alzheimer disease (AD). This follows the FDA’s January 2023 decision to approve Leqembi via the accelerated approval pathway, and the March 2023 decision to grant Leqembi priority review for approval with the prescription drug user fee act (PDUFA) action date of July 6, 2023.

The approval is based on data from the phase 3 Clarity AD clinical trial (NCT03887455) which evaluated the efficacy of Leqembi to treat patients with early AD. Clarity AD was a randomized, placebo-controlled, double-blind, parallel-group study in 1906 participants with AD who were assigned to receive either a 10 mg/kg dose of Leqembi administered as an IV infusion or placebo once every 2 weeks. The primary outcome was change from baseline in the Washington University Clinical Dementia Rating scale sum of boxes (CDR-SB) score, which measures cognitive and functional ability. After the trial period of 18 months, participants who received Leqembi showed reduced functional and cognitive decline compared to their placebo-receiving counterparts. Additionally, treatment with Leqembi was associated with improvements in secondary outcomes, including reduction of amyloid beta (Aβ) plaques visualized in positron emission tomography (PET) scans and improvements in scores on the Alzheimer’s Disease Assessment Scale (ADDS) and Alzheimer’s Disease Composite Score (ADCOMS) instruments.

The treatment could "give people in the early stages of Alzheimer’s more time to maintain their independence and do the things they love," Joanne Pike, President and CEO of the Alzheimer’s Association, said in a statement.

Leqembi is a humanized immunoglobulin gamma 1 (lgG1) monoclonal antibody directed against aggregated soluble (“protofibril”) and insoluble forms of Aβ for the treatment of those diagnosed with AD with mild cognitive impairment or mild dementia stage of disease and confirmed presence of Aβ pathology.