The latest findings for lecanemab-irmb (Leqembi), for early Alzheimer’s disease, were presented at the Clinical Trials for Alzheimer’s Disease Conference – Eisai + Biogen

Eisai Co., Ltd and Biogen Inc. announced  that the latest findings for lecanemab-irmb (U.S. brand name: Leqembi), an anti-amyloid beta (Aβ) protofibril antibody for the treatment of early Alzheimer’s disease (AD), were presented at the Clinical Trials for Alzheimer’s Disease Conference (CTAD), held in Madrid, Spain, and virtually.

Benefits of Continued Treatment with Lecanemab for People with Early AD
In July 2024 at the Alzheimer’s Association International Conference (AAIC) 2024, results from the open-label long-term extension study (OLE) following the core study of the lecanemab Phase III Clarity AD study were presented, showing that the mean change from baseline in CDR-SB (global cognitive and functional scale) in the lecanemab treated group relative to the placebo group was -0.45 at 18 months, and at 36 months, this expanded to -0.95 compared to a prespecified natural history  cohort of AD. There was a 30% reduction in the relative risk of progressing to the next disease stage In addition, the tau PET substudy of the lecanemab Phase III Clarity AD clinical study showed that with three (3) years of continuous treatment with lecanemab, 59% of patients with no or low tau accumulation in the brain (no tau/low tau) at baseline showed improvement or no decline, and 51% showed improvement from baseline on the Clinical Dementia Rating-Sum of Boxes (CDR-SB) global cognitive and functional scale.

Lecanemab Treatment for Early AD: Insights from Long-Term U.S. Clinical Studies
Dr. Marwan Noel Sabbagh, Moreno Family Chair for Alzheimer’s Research and Vice Chairman for Research and Professor, Department of Neurology, Barrow Neurological Institute, presented outcomes of an analysis of the use of lecanemab treatment between January 6, 2023, and July 30, 2024, based on payment claims data from the Komodo Research Database, a medical database in the U.S. In the U.S., lecanemab is used in accordance with the US FDA-approved indication, dosing, and monitoring guidelines. The analysis found that access to lecanemab treatment is expanding and highlighted opportunities to improve access in rural areas and educational outreach for underserved populations.

Dr. David Watson of the Alzheimer’s Research and Treatment Center reported on patients who continued to receive lecanemab treatment following the Phase II Study 201 and Phase III Clarity AD study. A total of 136 patients participated in both studies at this center, and 66 patients chose to continue lecanemab therapy, with 13 patients receiving treatment for more than five (5) years and 40 patients receiving treatment for more than three (3) years. More than half of the patients (15/24) who continued treatment with lecanemab for more than three (3) years after the core phase remained in their initial stage of disease. Further, in a survey of 11 patients (or their caregivers) who received lecanemab treatment for more than five (5) years, all patients responded that they were “very satisfied” or “satisfied” with lecanemab treatment. In addition, between 45% and 73% of patients responded that lecanemab treatment made them feel more positive about their daily life, social activities, memory, etc. “frequently” or “very often. No new long-term safety findings were observed in these multi-year studies.

Progress in the AHEAD 3-45 Study: Improving Screening Eligibility Using Blood Biomarkers and Completing Patient Enrollment
AHEAD 3-45 is a Phase III clinical study for individuals with preclinical AD, meaning they are clinically unimpaired but have intermediate or elevated levels of amyloid in their brains. In the study, blood tests, cognitive function tests (PACC-5), amyloid PET, MRI, and tau PET were used for screening. Based on the amount of Aβ accumulation in the brain as determined by amyloid PET, subjects were assigned to two (2) trials with different dose settings: the A3 trial, for those with borderline Aβ levels in the brain, and the A45 trial, for those with positive Aβ levels in the brain. Screening with blood biomarker tests was important to improve eligibility for amyloid PET testing in subjects without cognitive impairment. Using plasma Aβ42/40 ratio and p-tau217/tau217 ratio in the initial screening reduced screening failure on amyloid PET from more than 70% to less than 30%. In particular, plasma p-tau217 was shown to correlate with amyloid PET, supporting its role as a useful blood biomarker to identify elevated amyloid in the brain. Enrollment for the AHEAD 3-45 study was completed in October 2024.