An observational study in Alzheimer's Disease, sponsored by Eisai Korea Inc.. Recruiting at 1 site in United States. Open to participants aged 19 Years and older. Per ClinicalTrials.gov, last updated 2026-04-21.
Sponsored by Eisai Korea Inc. (part of Eisai Co., Ltd.) · Observational
Among 46 studies in Alzheimer Disease by Eisai Co., Ltd. — 7 open to participants now, 12 under way, 2 of them phase 3. Alzheimer Disease · Eisai Co., Ltd..
Among the 46 studies in Alzheimer Disease by Eisai Co., Ltd., this one is the 6th largest by planned enrollment of the 15 observational ones that give a count, is one of 2 that started in 2025, is one of 15 observational ones, reaches primary completion later than 6 of the 11 other live ones, and was the 40th registered.
3,967 studies on the registry are indexed under Alzheimer Disease; 928 are open to participants now.
Browse Alzheimer Disease studies →7 of the 46 studies in Alzheimer Disease by Eisai Co., Ltd. are open now, in 4 countries. Recruiting first, the newest first:
Eisai Limited · Sites in Canada
Eisai Inc. · Sites in United States
Eisai Co., Ltd. · Sites in Japan
Ages 18+
Eisai Limited · Sites in United Kingdom
Eisai Inc. · Sites in United States
By country, each count listing its studies:
Of the 642 Alzheimer Disease studies recruiting now, 283 (44%) set no upper age limit and 55 (9%) stop at 75 or younger; 34 take children under 18; 284 take healthy volunteers.
This study: 19 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
46 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 9 · Phase 2 6 · Phase 3 8 · Phase 4 9
First in 2001; this study’s year is marked. 2 started in 2025.
By drug class, each counting the studies that test any of its medicines:
This study's planned enrollment of 3,000 is above the median of 200 across 815 observational studies indexed under Alzheimer Disease.
Median enrollment 99 across the 30 interventional studies, 2,000 across the 15 observational. Of the 33 that completed or were terminated, 11 (33%) have results posted.
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This study is registered under Eisai Korea Inc., one of the names counted as Eisai Co., Ltd.. Under that name alone:
Eisai Korea Inc. is the lead sponsor of 31 studies on the registry; 2 are open to participants now.
2 of the studies in Alzheimer Disease by Eisai Co., Ltd. that are under way reach primary completion within a year, 1 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT03887455Phase 3Eisai Inc.A Study to Confirm Safety and Efficacy of Lecanemab in Participants With Early Alzheimer's Disease | 2026-12-31 |
| NCT06602258Eisai Inc.A Study of E2814 With Concurrent Lecanemab Treatment in Participants With Early Alzheimer's Disease | 2026-12-03 |
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Among the 46 studies in Alzheimer Disease by Eisai Co., Ltd., from their registry updates:
This tab as a report to print or save as PDF → With an account.
The primary purpose of this study is to evaluate safety of LEQEMBI in the real-world clinical setting as reported by events of amyloid-related imaging abnormalities (ARIA)-edema (ARIA-E), ARIA-hemosiderin deposition (ARIA-H), symptomatic ARIA-E, symptomatic ARIA-H, and intracerebral hemorrhage (ICH) greater-than 1 centimeter (cm) in patients treated with LEQEMBI.
Patients with alzheimer's disease prescribed LEQEMBI based on the approved prescribing information in South Korea and clinical judgement.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with alzheimer's disease treated with LEQEMBI in accordance with the approved prescribing information by a physician in routine clinical practice (postmarketing). Data will be collected from the JOY-ALZ registry.
Other: No Intervention
This is a non-interventional study.
Incidence of Adverse Events of Special Interest (AESIs)
AESI will include ARIA-E, ARIA-H, symptomatic ARIA-E, symptomatic ARIA-H, and ICH greater-than 1 cm.
Time frame: Up to 6 years
Exposure-adjusted Incidence Rate of AESIs
AESI will include ARIA-E, ARIA-H, symptomatic ARIA-E, symptomatic ARIA-H, and ICH greater-than 1 cm.
Time frame: Up to 6 years
Incidence of Adverse Events (AEs), Adverse drug reactions (ADRs), Serious Adverse Events (SAEs), Serious Adverse Drug Reactions (SADRs)
Time frame: Up to 6 years
Exposure-Adjusted Incidence Rate of AEs, ADRs, SAEs, SADRs
Time frame: Up to 6 years
Incidence of AEs and ADRs That are not Reflected in the Approved Prescribing Information
Time frame: Up to 6 years
Exposure-Adjusted Incidence Rate of AEs and ADRs That are not Reflected in the Approved Prescribing Information
Time frame: Up to 6 years
Incidence of ARIA-Related Events by Baseline Characteristics
Baseline characteristics include APOE4 genotype status, baseline magnetic resonance imaging (MRI) findings, prior Alzheimer's disease treatments, and antithrombotic therapy.
Time frame: Up to 6 years
Exposure-Adjusted Incidence Rate of ARIA-Related Events by Baseline Characteristics
Baseline characteristics include APOE4 genotype status, baseline MRI findings, prior Alzheimer's disease treatments, and antithrombotic therapy.
Time frame: Up to 6 years
Incidence of AEs by Baseline Characteristics
Baseline characteristics will include age, medical history, comorbidities, and concomitant medications.
Time frame: Up to 6 years
Exposure-Adjusted Incidence Rate of AEs by Baseline Characteristics
Baseline characteristics will include age, medical history, comorbidities, and concomitant medications.
Time frame: Up to 6 years
Plan to share: Yes — Eisai's data sharing commitment and further information on how to request data can be found on our website http://eisaiclinicaltrials.com/.
No publications or documents are linked to this record.
Started Feb 2025 (actual). Primary completion is estimated for Sep 2029, 55 months after the start.
Of 41 industry-sponsored observational studies under Alzheimer Disease, half reached primary completion within 34 months of starting (the median), counting those still running; a quarter within 20 and three quarters within 63. This study's planned 55 months is above that.
Counting every sponsor, half of 405 studies reached it within 67 months; a quarter within 35 and three quarters within 171.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
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