FDA Approves LEQEMBI® (lecanemab-irmb) IV Maintenance Dosing for the Treatment of Early Alzheimer's Disease

Core Insights - The FDA has approved the Supplemental Biologics License Application for LEQEMBI, allowing for once every four weeks maintenance dosing after an initial 18-month treatment phase [1][3][31] - LEQEMBI is indicated for early Alzheimer's disease, specifically for patients with mild cognitive impairment or mild dementia [7][31] - Ongoing treatment with LEQEMBI can slow disease progression and prolong therapeutic benefits, as it continuously clears toxic protofibrils and amyloid plaques [2][5][31] Group 1: Approval and Indications - LEQEMBI is approved in multiple countries including the U.S., Japan, China, and several others, with applications submitted in 17 regions [3][30] - The treatment received a positive opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use in November 2024 [3][30] - The FDA has also accepted a Supplemental Biologics License for a subcutaneous autoinjector for weekly maintenance dosing, with a PDUFA action date set for August 31, 2025 [3] Group 2: Clinical Efficacy - In the Clarity AD study, LEQEMBI reduced cognitive decline on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) by 27% at 18 months compared to placebo [31] - The mean change from baseline at 18 months was -0.45 on the CDR-SB scale, indicating a statistically significant benefit [31] - The treatment also showed a 37% improvement in the Activities of Daily Living Scale for Mild Cognitive Impairment compared to placebo [31] Group 3: Mechanism of Action - LEQEMBI works by continuously clearing both protofibrils and amyloid plaques, addressing the neurotoxic processes that contribute to Alzheimer's disease [2][5] - The treatment aims to maintain cognitive function and independence for patients by reducing neuronal injury [5][6] Group 4: Safety and Monitoring - The incidence of amyloid-related imaging abnormalities (ARIA) was reported at 21% for LEQEMBI, with symptomatic ARIA occurring in 3% of patients [12][13] - Monitoring guidelines recommend baseline brain MRI and periodic assessments to manage ARIA risks effectively [23] - Infusion-related reactions were observed in 26% of patients receiving LEQEMBI, with most cases occurring during the first infusion [25][27]