CompletedPhase 2Results posted

Evaluation of the Efficacy of Varenicline on Cognition, Safety, Tolerability and Pharmacokinetics in Subjects With Mild-to-Moderate Alzheimer's Disease

A Phase 2 Multicenter, Double-Blind, Placebo-Controlled, Crossover Trial of Varenicline Tartrate (CP-526,555) in Patients With Mild to Moderate Alzheimer's Disease

Lead sponsor

Pfizer

Asset

Varenicline

Listed sites

Recruiting sites

Enrollment

actual

Study population

Alzheimer’s disease

Key I/E criterion

•Alzheimer's disease

Primary endpoint

•ADAS-Cog

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 IDA3051101

NCT IDNCT00744978

Timeline

Milestones

Study first posted2008-09-01estimated

Study start2009-07 (month precision)

Primary completion2010-11actual (month precision)

Study completion2010-11actual (month precision)

Last update posted2011-11-22estimated

Results first posted2011-11-22estimated

Assets

Drug assets

Varenicline

Study populations

Who this study enrolls

Alzheimer’s disease

Eligibility

Who can enroll

Minimum age55 Years

Maximum age85 Years

SexAll

Healthy volunteersNot accepted

Inclusion criteria

•Males or females, age 55-85

•Diagnosis of probable Alzheimer's disease, consistent with criteria from both: 1) National Institute of Neurological and Communicable Disease and Stroke and Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) and 2) Diagnostic and Statistical Manual of Mental Disorders (DSM IV)

•Mini-mental status exam score of 14-26 inclusive

•Rosen-Modified Hachinski Ischemia Score of < or = 4

Exclusion criteria

•Diagnosis or history of other dementia or neurodegenerative disorders

•Diagnosis or history of clinically significant cerebrovascular or cardiovascular disease

•Subjects with pulmonary disease or evidence of clinically significant pulmonary symptoms

Endpoints (44)

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

Memory

Global cognition

Executive function / language

Other (unclassified)

Behavior / neuropsychiatric

Other clinical outcomes

Global cognition

8 endpoints

Primary/protocol endpoint

Alzheimer's Disease Assessment Scale-Cognitive Subscale 75 (ADAS-Cog 75) at Week 6

Time frame:Week 6

ADAS-Cog

concentration, descriptive

Primary/registry result

Alzheimer's Disease Assessment Scale-Cognitive Subscale 75 (ADAS-Cog 75) at Week 6

Time frame:Week 6

ADAS-Cog

concentration, descriptive

Posted result

Group	Value (least_squares_mean), units on scale	Standard error
Vareniclinen=53 Participants	18.07	0.942
Placebon=55 Participants	18.49	0.939

Mean Difference (Final Values)-0.4295% CI-1.37 - 0.53p0.3873ANCOVA

Secondary/protocol endpoint

Alzheimer's Disease Assessment Scale-Cognitive Subscale 75 (ADAS-Cog 75) at Week 3

Time frame:Week 3

ADAS-Cog

concentration, descriptive

Secondary/protocol endpoint

Alzheimer's Disease Assessment Scale-Cognitive Subscale 70 (ADAS-Cog 70) at Week 3

Time frame:Week 3

ADAS-Cog

descriptive

Secondary/protocol endpoint

Alzheimer's Disease Assessment Scale-Cognitive Subscale 70 (ADAS-Cog 70) at Week 6

Time frame:Week 6

ADAS-Cog

descriptive

Secondary/registry result

Alzheimer's Disease Assessment Scale-Cognitive Subscale 75 (ADAS-Cog 75) at Week 3

Time frame:Week 3

ADAS-Cog

concentration, descriptive

Posted result

Group	Value (least_squares_mean), units on scale	Standard error
Vareniclinen=58 Participants	19.87	0.935
Placebon=54 Participants	19.31	0.941

Mean Difference (Final Values)0.5595% CI-0.39 - 1.49p0.2465ANCOVA

Secondary/registry result

Alzheimer's Disease Assessment Scale-Cognitive Subscale 70 (ADAS-Cog 70) at Week 3

Time frame:Week 3

ADAS-Cog

descriptive

Posted result

Group	Value (least_squares_mean), units on scale	Standard error
Vareniclinen=58 Participants	19.60	0.880
Placebon=54 Participants	19.01	0.885

Mean Difference (Final Values)0.5995% CI-0.33 - 1.50p0.2092ANCOVA

Secondary/registry result

Alzheimer's Disease Assessment Scale-Cognitive Subscale 70 (ADAS-Cog 70) at Week 6

Time frame:Week 6

ADAS-Cog

descriptive

Posted result

Group	Value (least_squares_mean), units on scale	Standard error
Vareniclinen=53 Participants	17.86	0.886
Placebon=55 Participants	18.23	0.884

Mean Difference (Final Values)-0.3795% CI-1.30 - 0.56p0.4339ANCOVA

Memory

18 endpoints

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 1

Time frame:Week 1

event count, event

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 3

Time frame:Week 3

event count, event

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 6

Time frame:Week 6

event count, event

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 1

Time frame:Week 1

threshold achievement, improvement

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 3

Time frame:Week 3

threshold achievement, improvement

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 6

Time frame:Week 6

threshold achievement, improvement

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 1

Time frame:Week 1

threshold achievement, improvement

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 3

Time frame:Week 3

threshold achievement, improvement

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 6

Time frame:Week 6

threshold achievement, improvement

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 1

Time frame:Week 1

event count, event

Posted result

Group	Value (least_squares_mean), errors	Standard error
Vareniclinen=59 Participants	38.52	2.586
Placebon=56 Participants	40.05	2.626

Mean Difference (Final Values)-1.5395% CI-6.68 - 3.62p0.5588ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 3

Time frame:Week 3

event count, event

Posted result

Group	Value (least_squares_mean), errors	Standard error
Vareniclinen=58 Participants	39.43	2.600
Placebon=54 Participants	43.57	2.656

Mean Difference (Final Values)-4.1595% CI-9.34 - 1.05p0.1173ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 6

Time frame:Week 6

event count, event

Posted result

Group	Value (least_squares_mean), errors	Standard error
Vareniclinen=53 Participants	41.67	2.668
Placebon=55 Participants	42.98	2.641

Mean Difference (Final Values)-1.3195% CI-6.58 - 3.96p0.6251ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 1

Time frame:Week 1

threshold achievement, improvement

Posted result

Group	Value (least_squares_mean), arcsine proportion correct	Standard error
Vareniclinen=59 Participants	0.94	0.031
Placebon=56 Participants	0.94	0.031

Mean Difference (Final Values)-0.0095% CI-0.05 - 0.05p0.9109ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 3

Time frame:Week 3

threshold achievement, improvement

Posted result

Group	Value (least_squares_mean), arcsine proportion correct	Standard error
Vareniclinen=58 Participants	0.96	0.031
Placebon=54 Participants	0.97	0.032

Mean Difference (Final Values)-0.0195% CI-0.06 - 0.04p0.6632ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 6

Time frame:Week 6

threshold achievement, improvement

Posted result

Group	Value (least_squares_mean), arcsine proportion correct	Standard error
Vareniclinen=53 Participants	0.95	0.032
Placebon=55 Participants	0.96	0.031

Mean Difference (Final Values)-0.0295% CI-0.07 - 0.04p0.5450ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 1

Time frame:Week 1

threshold achievement, improvement

Posted result

Group	Value (least_squares_mean), arcsine proportion correct	Standard error
Vareniclinen=59 Participants	0.83	0.015
Placebon=56 Participants	0.81	0.016

Mean Difference (Final Values)0.0295% CI-0.02 - 0.05p0.2799ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 3

Time frame:Week 3

threshold achievement, improvement

Posted result

Group	Value (least_squares_mean), arcsine proportion correct	Standard error
Vareniclinen=58 Participants	0.82	0.016
Placebon=54 Participants	0.82	0.016

Mean Difference (Final Values)0.0095% CI-0.03 - 0.04p0.9675ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 6

Time frame:Week 6

threshold achievement, improvement

Posted result

Group	Value (least_squares_mean), arcsine proportion correct	Standard error
Vareniclinen=53 Participants	0.83	0.016
Placebon=55 Participants	0.84	0.016

Mean Difference (Final Values)-0.0195% CI-0.05 - 0.02p0.5008ANCOVA

Executive function / language

6 endpoints

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 1

Time frame:Week 1

descriptive

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 3

Time frame:Week 3

descriptive

Secondary/protocol endpoint

Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 6

Time frame:Week 6

descriptive

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 1

Time frame:Week 1

descriptive

Posted result

Group	Value (least_squares_mean), log10 millisecond	Standard error
Vareniclinen=59 Participants	2.79	0.011
Placebon=56 Participants	2.80	0.011

Mean Difference (Final Values)-0.0195% CI-0.03 - 0.01p0.2245ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 3

Time frame:Week 3

descriptive

Posted result

Group	Value (least_squares_mean), log10 millisecond	Standard error
Vareniclinen=58 Participants	2.79	0.011
Placebon=54 Participants	2.80	0.011

Mean Difference (Final Values)-0.0195% CI-0.03 - 0.01p0.4974ANCOVA

Secondary/registry result

Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 6

Time frame:Week 6

descriptive

Posted result

Group	Value (least_squares_mean), log10 millisecond	Standard error
Vareniclinen=52 Participants	2.79	0.012
Placebon=55 Participants	2.79	0.011

Mean Difference (Final Values)0.0095% CI-0.02 - 0.02p0.8525ANCOVA

Behavior / neuropsychiatric

4 endpoints

Secondary/protocol endpoint

Neuropsychiatric Inventory (NPI) Total Score at Week 3

Time frame:Week 3

Neuropsychiatric Inventory (NPI)

event count, event

Secondary/protocol endpoint

Neuropsychiatric Inventory (NPI) Total Score at Week 6

Time frame:Week 6

Neuropsychiatric Inventory (NPI)

event count, event

Secondary/registry result

Neuropsychiatric Inventory (NPI) Total Score at Week 3

Time frame:Week 3

Neuropsychiatric Inventory (NPI)

event count, event

Posted result

Group	Value (least_squares_mean), scores on scale	Standard error
Vareniclinen=59 Participants	2.97	0.845
Placebon=54 Participants	2.29	0.858

Mean Difference (Final Values)0.6895% CI-0.57 - 1.92p0.2852ANCOVA

Secondary/registry result

Neuropsychiatric Inventory (NPI) Total Score at Week 6

Time frame:Week 6

Neuropsychiatric Inventory (NPI)

event count, event

Posted result

Group	Value (least_squares_mean), scores on scale	Standard error
Vareniclinen=54 Participants	3.82	0.857
Placebon=55 Participants	2.55	0.855

Mean Difference (Final Values)1.2895% CI0.02 - 2.53p0.0468ANCOVA

Other clinical outcomes

2 endpoints

Secondary/protocol endpoint

Mean Clinical Global Impression - Improvement (CGI-I) Score at Week 6

Time frame:Week 6

descriptive

Secondary/registry result

Mean Clinical Global Impression - Improvement (CGI-I) Score at Week 6

Time frame:Week 6

descriptive

Posted result

Group	Value (least_squares_mean), units on a scale	Standard error
Vareniclinen=54 Participants	3.71	0.103
Placebon=55 Participants	3.70	0.102

Mean Difference (Final Values)0.0095% CI-0.26 - 0.27p0.9745ANCOVA

Difference from placebo analyzed using a mixed effects linear model with subject (nested within sequence) as a random effect, and stratum, site, period, sequence, and treatment as fixed effects.

Other (unclassified)

6 endpoints

Secondary/protocol endpoint/low confidence

Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 1

Time frame:Week 1

descriptive

Secondary/protocol endpoint/low confidence

Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 3

Time frame:Week 3

descriptive

Secondary/protocol endpoint/low confidence

Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 6

Time frame:Week 6

descriptive

Secondary/registry result/low confidence

Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 1

Time frame:Week 1

descriptive

Posted result

Group	Value (least_squares_mean), log10 millisecond	Standard error
Vareniclinen=59 Participants	2.65	0.015
Placebon=56 Participants	2.64	0.015

Mean Difference (Final Values)0.0095% CI-0.02 - 0.03p0.8811ANCOVA

Secondary/registry result/low confidence

Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 3

Time frame:Week 3

descriptive

Posted result

Group	Value (least_squares_mean), log10 millisecond	Standard error
Vareniclinen=58 Participants	2.65	0.015
Placebon=54 Participants	2.63	0.015

Mean Difference (Final Values)0.0295% CI-0.00 - 0.05p0.0830ANCOVA

Secondary/registry result/low confidence

Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 6

Time frame:Week 6

descriptive

Posted result

Group	Value (least_squares_mean), log10 millisecond	Standard error
Vareniclinen=53 Participants	2.64	0.015
Placebon=55 Participants	2.65	0.015

Mean Difference (Final Values)-0.0095% CI-0.03 - 0.02p0.7226ANCOVA

Publications (1)

Bibliography

Records linked to this trial through ClinicalTrials.gov references, PubMed NCT search, and curated study seeds. 'Canonical' marks design/result papers; others are registry references or candidates.

Registry references + supporting bibliography

Kim SY, Choi SH, Rollema H, Schwam EM, McRae T, Dubrava S, Jacobsen J. Phase II crossover trial of varenicline in mild-to-moderate Alzheimer's disease. Dement Geriatr Cogn Disord. 2014;37(3-4):232-45. doi: 10.1159/000355373. Epub 2013 Nov 14.
PMID24247022via DERIVED

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.