Eisai Presented New Analyses of ARIA and QOL on Lecanemab in Clarity AD at the AD/PD™ 2023 Annual Meeting

Tokyo and Cambridge, Mass. — Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, “Eisai”) and Biogen Inc. (Nasdaq: BIIB, Corporate headquarters: Cambridge, Massachusetts, CEO: Christopher A. Viehbacher, “Biogen”) announced that Eisai presented new analyses on amyloid-related imaging abnormalities (ARIA) with the use of antiplatelet and anticoagulant medications, isolated ARIA-H, and caregiver burden and health-related quality of life (QOL), from the results of Eisai’s Phase 3 Clarity AD study of lecanemab (generic name, U.S. brand name: LEQEMBI™), an anti-amyloid-β (Aβ) protofibril* antibody, at the 2023 International Conference on Alzheimer’s and Parkinson’s Diseases annual meeting AD/PD™.

Clarity AD was a global confirmatory Phase 3 placebo-controlled, double-blind, parallel-group, randomized study in 1,795 people with early Alzheimer’s disease (AD) (lecanemab group: 10 mg/kg bi-weekly IV treatment: 898, placebo group: 897). Lecanemab met the primary endpoint and all key secondary endpoints with highly statistically significant results. In November 2022, results of the Clarity AD study were presented at the Clinical Trials on Alzheimer’s Disease (CTAD) conference and simultaneously published in the peer-reviewed medical journal, The New England Journal of Medicine.

  1. Lecanemab Phase 3 Clarity AD Trial: ARIA With the Use of Antiplatelets or Anticoagulants in Early Alzheimer’s Disease

    In the Clarity AD study, ARIA rates were higher for patients receiving lecanemab compared to those on placebo. The objective of this analysis was to evaluate antiplatelet and anticoagulant medication use in participants who experienced either ARIA-E (edema) or ARIA-H (combined cerebral microhemorrhages, superficial siderosis, and intracerebral hemorrhages >1 cm in diameter).

    The risks of ARIA appear slightly higher in the placebo group with antiplatelet or with anticoagulants relative to placebo subjects not on anticoagulants (no antiplatelet or anticoagulation: 8.9%, antiplatelet: 9.7%, anticoagulation (anticoagulation alone or with antiplatelet): 10.8%). ARIA rates may be slightly lower in those on lecanemab treated with antiplatelet or with anticoagulation, relative to lecanemab treated subjects not with antiplatelet or with anticoagulation (no antiplatelet or anticoagulation: 21.8%, antiplatelet: 17.9%, anticoagulation: 13.3%).

    The incidence of ARIA-E was 13.1% in the lecanemab group and 1.5% in the placebo group when no antiplatelet or anticoagulant medication was used, 10.4% in the lecanemab group and 0.84% in the placebo group when antiplatelet medication was used, and 4.8% in the lecanemab group and 2.7% in the placebo group when anticoagulant medication was used.

    Because intracerebral hemorrhage >1cm have been observed in patients taking lecanemab, additional caution should be exercised when considering administration of antithrombotics or a thrombolytic agent.

    In Clarity AD, ARIA did not occur more frequently in lecanemab-treated participants on antiplatelet or anticoagulant drugs compared to lecanemab-treated participants that were not on either.

  2. Isolated ARIA-H in Patients Treated with Lecanemab in the Phase 3 Clarity AD Study in Early Alzheimer’s Disease

    The objective of this analysis was to describe the occurrences and timing of isolated ARIA-H events (i.e., those events not occurring temporally concurrent with ARIA-E). The incidence of overall ARIA-H was 17.3% in the lecanemab group and 9.0% in the placebo group, and the incidence of isolated ARIA-H was similar in the lecanemab (8.9%) and placebo (7.8%) groups in Clarity AD. While ARIA-H concurrent with ARIA-E occurred early in the treatment as expected given timing of ARIA-E, isolated ARIA-H in both the placebo and lecanemab groups were infrequent and occurred at a steady rate over 18 months of treatment. The incidence of isolated ARIA-H increased with number of ApoEε4 alleles in both placebo (noncarriers: 3.8%; heterozygotes: 7.3%; homozygotes: 18.0%), and lecanemab group (noncarriers: 8.3%; heterozygotes: 8.4%; homozygotes: 12.1%). On the other hand, it was found that the ApoEε4 carrier status did not impact the timing of overall occurrence of ARIA-H.

    In Clarity AD, the pattern of occurrence of isolated ARIA-H in lecanemab group was similar to that in placebo group.

  3. Lecanemab Clarity AD: Quality-of-Life Results from a Randomized, Double-Blind Phase 3 Trial in Early Alzheimer’s Disease

    The objective of this analysis was to describe the health-related quality-of-life (HRQoL) pre-specified exploratory results from Clarity AD. HRQoL by subject was measured using the European Quality of Life–5 Dimensions (EQ-5D-5L**) and Quality of Life in AD (QOL-AD***) scales at baseline and every 6 months post-baseline. QOL-AD was also assessed for the subject by the care partner. Additionally, care partners were administered the Zarit Burden Interview**** every 6 months to assess care partner burden associated with dementia.

    At month 18, adjusted mean change from baseline in EQ-5D-5L and QOL-AD of subject showed 49% and 56% less decline, respectively. Care partner burden measured Zarit Burden Interview and QOL-AD by partner resulted in 38% and 23% less decline at 18 months, respectively. Assessment results were consistent across ApoE genotypes.

    The results of the Clarity AD Health-related QoL measures presented additional evidence for meaningful benefits of lecanemab treatment to patients and care partners.

Eisai serves as the lead of lecanemab development and regulatory submissions globally with both Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority.

*  Protofibrils are large Aβ aggregated soluble species of 75-5000 Kd.1
**  The European Quality of Life-5 Dimensions (EQ-5D-5L) is used as a patient-reported measure of quality of life and consists of five domains (degree of mobility, personal care, daily living, pain/discomfort and anxiety/blushing).
*** Quality of Life in AD (QOL-AD) is a quality-of-life index specific to dementia.
**** The Zarit Burden Interview is a scale to measure caregiver burden.


1 Söderberg, L., Johannesson, M., Nygren, P. et al. Lecanemab, Aducanumab, and Gantenerumab — Binding Profiles to Different Forms of Amyloid-Beta Might Explain Efficacy and Side Effects in Clinical Trials for Alzheimer’s Disease. Neurotherapeutics (2022). https://doi.org/10.1007/s13311-022-01308-6. Accessed March 23, 2023

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