Objective:

To report real-world data on patients with early Alzheimer’s disease (AD) treated with lecanemab in our geriatric clinical practice.

Background:

Lecanemab, a monoclonal antibody binding with high affinity to protofibrils of Aβ-protein, significantly reduced amyloid biomarkers and slowed clinical decline on multiple measures of cognition and function for up to 48 months in the phase 3 Clarity AD trial.

Design/Methods:

This retrospective case series evaluated individuals with early AD administered lecanemab treatment over the past 28 months at Bristol Health. Data collection included patient characteristics, efficacy assessments (Montreal Cognitive Assessment [MoCA], Clinical Dementia Rating Scale Sum of Boxes [CDR-SB] and global score [CDR-global], and Functional Activities Questionnaire [FAQ]). Feedback on experience with subcutaneous and intravenous lecanemab were collected via a survey. 

Results:

Overall, 53 individuals with early AD (mild AD:33; mild cognitive impairment:20) treated with lecanemab for a mean duration of 10 months were included. Mean time from diagnosis to treatment of 5.8 months, decreasing over time (mean time 2023: 9.7 months; 2024: 5.5 months; 2025: 3.6 months). For the 26 patients with MoCA baseline and post-baseline scores, 10 patients had improved scores and 10 had stable scores (within 10% of baseline). Among the 17 patients with CDR-SB baseline and post-baseline scores, 3 patients had improved scores and 7 had stable scores. Five of 13 patients who had post-baseline FAQ assessments had improved or remained stable. CDR global scores were improved or stable for 16/18 patients (improved:1; stable:15). Five (9.4%) ARIA-E cases (1 symptomatic; 4 resolved) and six (11.3%) ARIA-H cases (1 symptomatic; 4/5 ARIA-H were isolated) were observed. Infusion related reactions occurred in 5 patients (9.4%). Patients reported feeling ‘very satisfied’ or ‘satisfied’ with lecanemab treatment.

Conclusions:

Lecanemab efficacy and safety profile was similar to that observed in clinical studies in our real-world geriatric clinical practice setting.