An observational study in Alzheimers Disease, sponsored by Eisai Limited. Not yet recruiting at 3 sites in United Kingdom. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Eisai Limited · Observational
The primary purpose of the study is to describe the incidence and severity of known adverse events (AEs), including Amyloid-Related Imaging Abnormalities Oedema/Effusion (ARIA-E), Amyloid-Related Imaging Abnormalities-Microhemorrhage and Haemosiderin Deposit (ARIA-H), intracerebral hemorrhage greater than (>) 1 centimeter (cm) in diameter, and anaphylaxis (stratified by apolipoprotein E4 variant [APOE4] genotype, concomitant antithrombotic therapy, and comorbid Cerebral Amyloid Angiopathy [CAA]), of LEQEMBI in routine clinical practice.
This is a Post-Authorisation Safety Study registry designed to evaluate the safety, benefit-risk profile, drug utilisation, and effectiveness of risk minimisation measures of LEQEMBI in patients with AD in routine clinical practice
The secondary purposes of the study are:
3,965 studies on the registry are indexed under Alzheimer Disease; 926 are open to participants now.
This study's planned enrollment of 400 is above the median of 200 across 814 observational studies indexed under Alzheimer Disease.
Browse Alzheimer Disease studies →Eisai Limited is the lead sponsor of 48 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Participants with AD who are prescribed LEQEMBI by a physician in routine clinical practice in the UK.
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:
-Participation or planning to participate in randomised controlled trials (RCTs) for mild cognitive impairment (MCI) or AD, and patients who have had prior exposure to anti-amyloid monoclonal antibody (mAb) treatment including prior use of lecanemab.
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.
Other: No Intervention
No intervention.
Incidence and Severity of ARIA-E, ARIA-H, Intracerebral Hemorrhage >1 cm in Diameter and Anaphylaxis
Time frame: Up to 3 years
Time to Progression to the Next Stage of Alzheimer's Disease (AD)
Time frame: Up to 3 years
Incidence and Severity of Serious Suspected Adverse Reactions and Adverse Reactions Leading to Discontinuation of LEQEMBI Treatment
Time frame: Up to 3 years
Drug Utilisation of LEQEMBI Based on Baseline Characteristics
Baseline demographics will include age/age group, sex, race, ethnicity, clinical disease stage, APOE4 genotypes, diagnosis of AD, baseline magnetic resonance imaging (MRI) findings consistent with a high risk of cerebral amyloid angiopathy (CAA), use of AD treatment, and use of concomitant antithrombotic medications at baseline.
Time frame: Up to 3 years
Duration of Treatment
Drug Utilization of LEQEMBI will be assessed by Duration of Treatment
Time frame: Up to 3 years
Incidence of Serious ARIA and ICH
Incidence of serious ARIA and ICH \>1 cm in diameter will be assessed
Time frame: Up to 3 years
Effectiveness of Risk Minimization Measures
Percentage of participants with use of antithrombotic medications, demonstrating compliance with magnetic resonance imaging (MRI) monitoring schedule, demonstrating compliance with dose suspension or discontinuation, and, physician compliance with the Summary of Product Characteristics (SmPC) and provision of participant with the Patient Alert Card (PAC) and Patient Information Leaflet (PIL).
Time frame: Up to 3 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.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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