Biogen and Eisai Say Four-Year Leqembi Data Further Slows Alzheimer’s Decline

Biogen Inc. and Eisai Co. unveiled four-year results for their anti-amyloid antibody Leqembi at the Alzheimer’s Association International Conference in Toronto. In the open-label extension of the 1,795-patient Clarity AD study, continuous treatment slowed clinical decline by 1.75 points on the Clinical Dementia Rating–Sum of Boxes versus the expected natural history of Alzheimer’s disease. Among patients with low tau levels, 56 percent showed improvement or no decline after four years. No new safety issues emerged, and rates of amyloid-related imaging abnormalities remained stable after the first year. The partners also presented data on a 360 mg weekly subcutaneous maintenance regimen delivered by autoinjector. Pharmacokinetic, efficacy and biomarker readouts matched those seen with the approved intravenous formulation, while injection reactions occurred in fewer than 1 percent of patients, potentially allowing home administration and reduced infusion-center time. Other companies used the meeting to spotlight advances in Alzheimer’s diagnostics and therapeutics. Acumen Pharmaceuticals reported that its pTau217 blood assay effectively screens patients for a planned Phase 2 trial of the oligomer-targeting antibody sabirnetug. NewAmsterdam Pharma said its cholesterol drug obicetrapib significantly lowered established Alzheimer’s biomarkers in the Phase 3 BROADWAY study, sending its shares higher. Taken together, the conference data underscore growing industry momentum toward earlier diagnosis and disease-modifying treatment options for Alzheimer’s.