New data presented at the Clinical Trials on Alzheimer's Disease (CTAD) congress in Madrid, Spain, by Eisai, partner of BioArctic AB, highlights the sustained benefits of lecanemab (Leqembi®) in patients with early Alzheimer's disease. The three-year findings indicate continued cognitive and functional benefits, with a maintained safety profile, reinforcing the potential of early intervention in Alzheimer's treatment.
Sustained Benefits of Lecanemab in Early Alzheimer's
Results from the open-label long-term extension (OLE) study, following the Phase 3 Clarity AD study, demonstrated that the mean change from baseline in CDR-SB (Clinical Dementia Rating-Sum of Boxes) in the lecanemab-treated group was -0.45 at 18 months compared to the placebo group. This benefit expanded to -0.95 compared to the ADNI population at 36 months. The data also indicated a 30% reduction in the risk of progressing to the next disease stage.
Furthermore, a tau PET substudy of Clarity AD revealed that 59% of patients with no or low tau accumulation in the brain at baseline showed improvement or no decline after three years of continuous lecanemab treatment. Additionally, 51% showed improvement from baseline on the CDR-SB scale.
Impact of Early Treatment Initiation
Clarity AD data presented at CTAD included additional measurements from three years of continuous lecanemab treatment in patients with low levels of amyloid accumulation in the brain at baseline (less than 60 centiloids). These data showed that 46% of patients improved or had no decline, and 33% showed improvement from baseline on the CDR-SB, with similar results for ADAS-Cog14 and on the ADCS MCI-ADL scales. These results suggest that earlier initiation of lecanemab treatment may have a positive impact on disease progression of early Alzheimer's disease patients and may provide continued benefits to these patients over the long term.
Safety Profile and ARIA Incidence
Continued lecanemab treatment over three years showed no new safety findings. Most Amyloid-related imaging abnormalities (ARIA) occurred in the first six months of treatment. After this period, ARIA rates were low and similar to those observed with placebo. The incidence of ARIA was higher in ApoE4 homozygotes compared to heterozygotes or non-carriers, but rates of new ARIA decreased after the completion of the 18-month core study, regardless of ApoE4 status.
Continued Treatment After Plaque Clearance
Clinical data and biomarkers such as Aβ42/40 ratio, pTau181, pTau217, and GFAP suggest that Alzheimer's disease does not stop progressing after plaque clearance. Data indicates that patients continue to benefit by remaining on treatment, potentially at a lower maintenance dose, which was shown to prevent reaccumulation of brain amyloid and worsening of plasma biomarkers.
AHEAD 3-45 Study Enrollment Completed
The AHEAD 3-45 study, a Phase 3 clinical trial for individuals with preclinical Alzheimer's disease, has completed patient enrollment. This study includes individuals with intermediate or elevated levels of amyloid in their brains. Screening with blood biomarker tests, particularly plasma p-tau217, improved eligibility for amyloid PET testing and reduced screening failure rates.
"The long-term data for lecanemab which our partner Eisai has presented are impressive," said Gunilla Osswald, CEO at BioArctic. "It shows that the patient benefit of lecanemab continues to increase over time, which is exactly what is expected from a disease-modifying treatment."
