An observational study in Alzheimer's Disease, sponsored by Eisai Taiwan Inc.. Not yet recruiting at 12 sites in Taiwan. Per ClinicalTrials.gov, last updated 2026-10-09.
Sponsored by Eisai Taiwan Inc. · Observational
The primary purpose of this study is to describe the incidence and severity of known adverse events, including amyloid-related imaging abnormalities (ARIA)-oedema/effusion (ARIA-E), ARIA-microhemorrhage and haemosiderin deposit (ARIA-H), intracerebral hemorrhage greater than 1 cm, and anaphylaxis (stratified by apolipoprotein E4 variant [APOE4] genotype, concomitant antithrombotic therapy, and comorbid cerebral amyloid angiopathy [CAA]), in participants treated with LEQEMBI in routine clinical practice in Taiwan.
To describe previously unknown adverse events related to long-term safety of LEQEMBI in routine clinical practice, which were not identified in clinical development, as assessed by serious suspected adverse reactions and adverse reactions leading to discontinuation of LEQEMBI treatment.
To describe progression to the next stage of Alzheimer's Disease (AD) in routine clinical practice.
To describe drug utilization of LEQEMBI and effectiveness of risk minimization measures in routine clinical practice.
3,765 studies on the registry are indexed under Alzheimer Disease; 881 are open to participants now.
This study's planned enrollment of 100 is below the median of 200 across 780 observational studies indexed under Alzheimer Disease.
Browse Alzheimer Disease studies →This is the only study on the registry with Eisai Taiwan Inc. as lead sponsor.
Counted across the registry records on this site, refreshed daily.
The study population comprises of participants with Alzheimer's Disease who are prescribed LEQEMBI in Taiwan and are enrolled into the PASS Registry either prior to initiation or after beginning of therapy.
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:
Patients with Alzheimer's Disease treated with LEQEMBI in routine clinical practice.
Other: No Intervention
This is a non-interventional study.
Incidence and Severity of Known Adverse Events (AEs)
Time frame: Up to 2 years
Incidence and Severity of Previously Unknown Adverse Events Related to the Long-Term Safety of LEQEMBI in Routine Clinical Practice
Incidence and severity of serious suspected adverse reactions and adverse reactions leading to discontinuation of LEQEMBI treatment.
Time frame: Up to 2 years
Time to Progression to the Next Stage of Alzheimer's Disease
The stages of disease are assessed by the clinician using tools that they use in routine clinical practice, and are mild cognitive impairment (MCI) due to AD, mild AD, moderate AD, or severe AD.
Time frame: Up to 2 years
Drug Utilization of LEQEMBI
Drug utilization will be assessed by baseline demographics, apolipoprotein E4 variant (APOE4) genotype, AD diagnosis, and baseline magnetic resonance imaging (MRI) findings, baseline antithrombotic use.
Time frame: Up to 2 years
Duration of Treatment
Drug Utilization of LEQEMBI will be assessed by Duration of Treatment
Time frame: Up to 2 years
Incidence of Serious ARIA and ICH
Incidence of serious ARIA and ICH \>1 cm in diameter will be assessed
Time frame: Up to 2 years
Effectiveness of Risk Minimization Measures
Effectiveness of Risk Minimization Measures will be assessed by the proportion of participants using antithrombotic medications during treatment, demonstrating compliance with the MRI monitoring schedule and with dose suspension or discontinuation of LEQEMBI for ARIA-E, ARIA-H, or ICH \>1 cm in diameter, and physician compliance with the package insert and providing educational materials to participants.
Time frame: Up to 2 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.
Start is estimated for Oct 2026; primary completion for Sep 2030, 47 months later.
Of 36 industry-sponsored observational studies under Alzheimer Disease, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 20 and three quarters within 63. This study's planned 47 months is above that.
Counting every sponsor, half of 387 studies reached it within 67 months; a quarter within 36 and three quarters within 140.
How these figures are worked out, and which studies are left out of them.
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 Sep 2026. You cannot join it, but the record below documents what was studied.
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