To provide real-world experience on the treatment of individuals with early Alzheimer’s disease with lecanemab.

Lecanemab is a monoclonal antibody targeting neurotoxic Aβ protofibrils and plaques, which reduces markers of amyloid and significantly slows clinical decline on multiple cognition and function measures.

We conducted a single-center, retrospective case series investigation in consecutive patients with confirmed early Alzheimer’s disease treated with lecanemab at the Clinical Trial Center of Abington Neurological Associates. Data collection included patient demographic characteristics, clinical history, lecanemab treatment exposure, safety, as well as time from diagnosis to treatment. Assessments included N-psych and functional scores and safety.

A total of 95 patients with early Alzheimer’s disease treated with lecanemab were included (47 with 6-month assessments at cutoff). Patients were majority Caucasian (89%), female (57%), with a mean age of 73 years. Most patients had mild Alzheimer’s disease (77%) and 72% were ApoE4 (60% heterozygotes; 12% homozygotes). The average duration of disease was 1.5 years (range:0.1–10 years). The mean time from diagnosis to first dose improved with experience and coverage (1^st half 2023:189 days; 2^nd half 2023: 104 days; 2024:84 days). At 6 months, N-psych (baseline:7.2; 6-months:2.5) and functional scores (baseline:2.5; 6-months:2.0) improved. Two patients were on aducanumab and successfully transitioned to lecanemab. The overall safety profile for lecanemab was similar to that observed in published clinical trials. There were 7 cases of ARIA-E (7%) and 2 ARIA-H (2%), with all but one resolved by the cutoff date.