TerminatedPhase 3Results posted

A Phase 3 Efficacy Study Of Dimebon In Patients With Moderate To Severe Alzheimer's Disease

A Phase 3, Multi-Center, Randomized, Double-Blind, Placebo-Controlled 26-Week Trial To Evaluate The Efficacy And Safety Of Dimebon In Patients With Moderate-To-Severe Alzheimer's Disease

Lead sponsor

Pfizer

Asset

Dimebon

Listed sites

Recruiting sites

Enrollment

actual

Study population

Alzheimer’s disease

Key I/E criterion

•Study partner/caregiver required

Primary endpoints

•The Severe Impairment Battery (SIB) Score•ADCS-Activities of Daily Living (ADCS-ADL)

Footprint

Where this trial recruits

Site locations as reported to ClinicalTrials.gov. Site count is not enrollment count; per-site enrollment is not available from source.

Identifiers

Registered as

Org study IDB1451006

NCT IDNCT00912288

Timeline

Milestones

Study first posted2009-06-03estimated

Study start2009-09 (month precision)

Primary completion2010-08actual (month precision)

Study completion2010-08actual (month precision)

Last update posted2012-10-02estimated

Results first posted2012-10-02estimated

Assets

Drug assets

Dimebon

Study populations

Who this study enrolls

Alzheimer’s disease

Eligibility

Who can enroll

Minimum age50 Years

SexAll

Healthy volunteersNot accepted

Inclusion criteria

•Are men and women ≥ 50 years of age with a diagnosis of Alzheimers disease.

•Have a Mini-Mental State Exam between 5 and 14 inclusive.

•Have been taking the medication memantine (ie., Namenda) for at least six months prior to this study.

•Must have a caregiver who assists the patient at least five days per week for at least three hours per day, who can accompany patient to study visits, and who has an intimate knowledge of the patient's health states and personal care

Exclusion criteria

•Have taken medicines for Alzheimers disease other than memantine (e.g., donepezil, rivastigmine, galantamine, tacrine) within 2 months prior to this study.

•Dementia other than Alzheimers disease.

•Any medical condition or reason that interferes with the ability of the patient to participate in or complete the trial or places the patient at undue risk, as judged by the study doctor.

Endpoints (20)

What's being measured

Protocol endpoints and posted registry outcome measures, grouped into outcome categories. Composite endpoints show their component event types. Standard codes (LOINC, SNOMED CT) are shown where available.

Coverage by outcome category

Behavior / neuropsychiatric

Global cognition

Caregiver / quality of life

Safety / tolerability / PK

Function / daily living

Global cognition

4 endpoints

Primary/protocol endpoint

Change From Baseline in the Severe Impairment Battery (SIB) Score at Week 26

Time frame:Baseline, Week 26

change from baseline, improvement

Primary/registry result

Change From Baseline in the Severe Impairment Battery (SIB) Score at Week 26

Time frame:Baseline, Week 26

change from baseline, improvement

Secondary/protocol endpoint

Change From Baseline in the Mini-Mental State Examination (MMSE) Score at Week 26

Time frame:Baseline, Week 26

Mini-Mental State Examination (MMSE)

change from baseline, improvement

Secondary/registry result

Change From Baseline in the Mini-Mental State Examination (MMSE) Score at Week 26

Time frame:Baseline, Week 26

Mini-Mental State Examination (MMSE)

change from baseline, improvement

Function / daily living

2 endpoints

Primary/protocol endpoint

Change From Baseline in the Alzheimer's Disease Cooperative Study - Activities of Daily Living (Severe) (ADCS-ADLsev) Score at Week 26

Time frame:Baseline, Week 26

ADCS-Activities of Daily Living (ADCS-ADL)

change from baseline, improvement

Primary/registry result

Change From Baseline in the Alzheimer's Disease Cooperative Study - Activities of Daily Living (Severe) (ADCS-ADLsev) Score at Week 26

Time frame:Baseline, Week 26

ADCS-Activities of Daily Living (ADCS-ADL)

change from baseline, improvement

Behavior / neuropsychiatric

6 endpoints

Secondary/protocol endpoint

Change From Baseline in the Neuropsychiatric Inventory (NPI) Total Score at Week 26

Time frame:Baseline, Week 26

Neuropsychiatric Inventory (NPI)

change from baseline, improvement

Secondary/protocol endpoint

Sum of the Delusions and Hallucinations Sub-domain Scores of the NPI

Time frame:Week 26

Neuropsychiatric Inventory (NPI)

event count, event

Secondary/protocol endpoint

Euro Quality of Life - 5 Domain (EQ-5D) Assessment

Time frame:Baseline, Weeks 12, 26

descriptive

Secondary/registry result

Change From Baseline in the Neuropsychiatric Inventory (NPI) Total Score at Week 26

Time frame:Baseline, Week 26

Neuropsychiatric Inventory (NPI)

change from baseline, improvement

Secondary/registry result

Sum of the Delusions and Hallucinations Sub-domain Scores of the NPI

Time frame:Week 26

Neuropsychiatric Inventory (NPI)

event count, event

Secondary/registry result

Euro Quality of Life - 5 Domain (EQ-5D) Assessment

Time frame:Baseline, Weeks 12, 26

descriptive

Caregiver / quality of life

4 endpoints

Secondary/protocol endpoint

Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-plus) Scores

Time frame:Week 26

change from baseline, improvement

Secondary/protocol endpoint

Resource Utilization in Dementia-Lite Version (RUD-Lite)

Time frame:Baseline, Weeks 12, 18, 26

event count, event

Secondary/registry result

Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-plus) Scores

Time frame:Week 26

change from baseline, improvement

Secondary/registry result

Resource Utilization in Dementia-Lite Version (RUD-Lite)

Time frame:Baseline, Weeks 12, 18, 26

event count, event

Safety / tolerability / PK

4 endpoints

Secondary/protocol endpoint

Population Pharmacokinetic (PK) Analysis

Time frame:Pre-dose, 0.5 to 1.5 hours, 2.5 to 3.5 hours post-dose at Week 12

descriptive

Secondary/protocol endpoint

Number of Participants With Adverse Events (AEs)

Time frame:Baseline up to Week 30 (follow-up)

event count, event

Secondary/registry result

Population Pharmacokinetic (PK) Analysis

Time frame:Pre-dose, 0.5 to 1.5 hours, 2.5 to 3.5 hours post-dose at Week 12

descriptive

Secondary/registry result

Number of Participants With Adverse Events (AEs)

Time frame:Baseline up to Week 30 (follow-up)

event count, event

Posted result

Group	Value (number), Participants	Reported bounds
Dimebonn=44 Participants	27	-
Placebon=42 Participants	18	-

Provenance

Sources

Trial identity, design, statusClinicalTrials.gov API v2

Snapshot dateJuly 21, 2026

Endpoint classificationDelfa ADRD endpoint taxonomy

Results tableClinicalTrials.gov results section

Trial facts come from public ClinicalTrials.gov records. Endpoint categories are Delfa's classification of those records, not a ClinicalTrials.gov field. All figures reflect the July 21, 2026 snapshot.