Lead sponsor
Eisai Inc.
25 Alzheimer’s disease and related dementias trials led. Source: ClinicalTrials.gov, as of July 21, 2026.
25
Trials led
3
Ongoing
8,901
Total enrollment
731
Sites
Distinct sites across this sponsor's lead trials. A site running several of them counts once, matching the map. Total enrollment sums each trial's reported enrollment, whether planned or actual.
Portfolio
How this sponsor's trials break down
Trials by phase
Phase 1
6
Phase 1/2
1
Phase 2
7
Phase 3
6
Phase 4
5
Trials by status
Active, not recruiting
3
Completed
20
Terminated
1
Withdrawn
1
Trials led
TrialEligibility highlightPhaseStatusEnrollment
Comparison of 23 mg Donepezil Sustained Release (SR) to 10 mg Donepezil Immediate Release (IR) in Patients With Moderate to Severe Alzheimer's DiseaseAlzheimer's diseasePh 3Completed1,467
AHEAD 3-45 Study: A Study to Evaluate Efficacy and Safety of Treatment With Lecanemab in Participants With Preclinical Alzheimer's Disease and Elevated Amyloid and Also in Participants With Early Preclinical Alzheimer's Disease and Intermediate AmyloidAmyloid biomarker required (PET)Ph 3Active, not recruiting1,400
Donepezil Hydrochloride (E2020) in Dementia Associated With Cerebrovascular DiseaseAge ≥41Ph 3Completed974
Open-Label Extension Study of 23 mg Donepezil SR in Participants With Moderate to Severe Alzheimer's DiseaseStudy partner/caregiver requiredPh 3Completed915
A Study to Evaluate Safety, Tolerability, and Efficacy of Lecanemab in Subjects With Early Alzheimer's DiseaseMCI due to AD / mild AD dementiaPh 2Completed856
Study To Evaluate the Efficacy, Safety and Tolerability of E2027 (Hereinafter Referred to as Irsenontrine) in Participants With Dementia With Lewy BodiesDementia with Lewy bodiesPh 2Completed326
Efficacy and Safety of Aricept in the Treatment of Severe Alzheimer's DiseaseAge ≥50Ph 3Completed229
A Study of E2814 With Concurrent Lecanemab Treatment in Participants With Early Alzheimer's DiseaseMCI due to AD / mild AD dementiaPh 2Active, not recruiting105
EARTH 413: A Study of Aricept in Hispanic Patients With Mild to Moderate Alzheimer's Disease (AD)Alzheimer's diseasePh 4Completed100
The Effectiveness And Safety Of Donepezil Hydrochloride (E2020) In Subjects With Mild To Severe Alzheimer's Disease Residing In An Assisted Living FacilityAlzheimer's diseasePh 4Completed97
Evaluation of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of E2609 in Healthy Subjects and an Elderly CohortHealthy volunteersPh 1Completed73
Dose-Finding Study To Evaluate Safety, Tolerability, and Efficacy of E2609 in Participants With Mild Cognitive Impairment Due to Alzheimer's Disease (Prodromal Alzheimer's Disease) and Mild to Moderate Dementia Due to Alzheimer's DiseaseMCI due to AD / prodromal ADPh 2Terminated70
Evaluation of E2609 in Subjects With Mild Cognitive Impairment or Mild Dementia Due to Alzheimer's Disease (Study: E2609-A001-101 Amendment 02)Alzheimer's diseasePh 1Completed65
Study of Lemborexant for Irregular Sleep-Wake Rhythm Disorder and Mild to Moderate Alzheimer's Disease DementiaAlzheimer's diseasePh 2Completed63
A Randomized, Double-blind, Placebo-controlled, Sequential Ascending, Single-dose Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of E2212 in Healthy SubjectsAge 18-55Ph 1Completed60
A Study Versus E2020 10mg Followed by an Open-label Extension Phase to Explore the Safety of E2020 SR 23 mg in Japanese Subjects With Severe Alzheimer's Type DementiaAlzheimer's diseasePh 2Completed45
Efficacy and Safety of Donepezil Hydrochloride (Aricept) in Vascular DementiaVascular dementiaPh 4Completed36
A Study of E2027 in Participants With Dementia With Lewy Bodies (DLB) or Parkinson's Disease Dementia (PDD) With or Without Amyloid CopathologyParkinson's disease dementiaPh 2Completed34
A Study to Evaluate the Pharmacokinetics of E2609 and Its Metabolites in Subjects With Mild and Moderate Hepatic Impairment Compared With Healthy SubjectsHealthy volunteersPh 1Completed32
An Study to Determine the Bioavailability of E2609 Tablets Compared to Capsules and the Effect of Food on AbsorptionAge 30-55Ph 1Completed18
A Study to Determine the Metabolism and Elimination of [14C]E2027 in Healthy Male ParticipantsAge 18-55Ph 1Completed8
A Study to Assess Safety and Target Engagement of E2814 in Participants With Mild to Moderate Cognitive Impairment Due to Dominantly Inherited Alzheimer's DiseasePSEN1/PSEN2/APP mutation requiredPh 1/2Completed8
Evaluating The Impact Of Donepezil Hydrochloride (Aricept) On Behavioral And Psychological Symptoms In Patients With Severe Alzheimer's DiseaseAlzheimer's diseasePh 4Withdrawnnot disclosed