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

Phase 2

Completed

Conditions: Alzheimer's Disease

Interventions: Drug: Varenicline
Drug: Placebo

Registration Number: NCT00744978

Lead Sponsor: Pfizer

Brief Summary: 1. Assess the efficacy of varenicline, relative to placebo, on a performance based measure of cognition in patients with mild to moderate Alzheimer's disease

2. Evaluate the effects of varenicline on clinically relevant measures including attention and executive function, behavior, and clinician rated global change.

3. Evaluate the safety and tolerability of varenicline, relative to placebo, in patients with mild to moderate Alzheimer's disease

4. Evaluate the pharmacokinetics of varenicline in patients with mild to moderate Alzheimer's disease.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 66

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Varenicline	Varenicline	-
Placebo	Placebo	-

Primary Outcome Measures

Name	Time	Method
Alzheimer's Disease Assessment Scale-Cognitive Subscale 75 (ADAS-Cog 75) at Week 6	Week 6	12-item scale to assess severity of cognitive impairment in AD. Items include word recall, naming objects and fingers, following commands, constructional praxis, ideational praxis, orientation, word recognition, spoken language ability, comprehension of spoken language, word finding difficulty in spontaneous speech, remembering test instructions, and concentration/distractibility. Total score range from 0-75 with 75 indicating worse cognition.

Secondary Outcome Measures

Name	Time	Method
Alzheimer's Disease Assessment Scale-Cognitive Subscale 75 (ADAS-Cog 75) at Week 3	Week 3	12-item scale to assess severity of cognitive impairment in AD. Items include word recall, naming objects and fingers, following commands, constructional praxis, ideational praxis, orientation, word recognition, spoken language ability, comprehension of spoken language, word finding difficulty in spontaneous speech, remembering test instructions, and concentration/distractibility. Total score range from 0-75 with 75 indicating worse cognition.
Alzheimer's Disease Assessment Scale-Cognitive Subscale 70 (ADAS-Cog 70) at Week 3	Week 3	11-item scale designed to assess the severity of cognitive impairments in AD subjects. Items include word recall, naming objects and fingers, following commands, constructional praxis, ideational praxis, orientation, word recognition, spoken language ability, comprehension of spoken language, word finding difficulty in spontaneous speech, and remembering test instructions. Total score range from 0-70 with 70 indicating worse cognition.
Alzheimer's Disease Assessment Scale-Cognitive Subscale 70 (ADAS-Cog 70) at Week 6	Week 6	11-item scale designed to assess the severity of cognitive impairments in AD subjects. Items include word recall, naming objects and fingers, following commands, constructional praxis, ideational praxis, orientation, word recognition, spoken language ability, comprehension of spoken language, word finding difficulty in spontaneous speech, and remembering test instructions. Total score range from 0-70 with 70 indicating worse cognition.
Mean Clinical Global Impression - Improvement (CGI-I) Score at Week 6	Week 6	CGI-I: 7-point clinician rated scale ranging from 1 (very much improved) to 7 (very much worse). Improvement is defined as a score of 1 (very much improved), 2 (much improved), or 3 (minimally improved) on the scale. Higher score = more affected.
Neuropsychiatric Inventory (NPI) Total Score at Week 3	Week 3	Caregiver interview-based rating scale assessing 12 behavioral disturbances occurring in dementia: delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability/lability, aberrant motor behavior, appetite/eating, and sleep. Each symptom score derived by frequency of symptoms \* severity of symptoms (range 0-12). Total score = sum of symptom scores; range: 0-144 with higher score indicating greater behavioral disturbances.
Neuropsychiatric Inventory (NPI) Total Score at Week 6	Week 6	Caregiver interview-based rating scale assessing 12 behavioral disturbances occurring in dementia: delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, elation/euphoria, apathy/indifference, disinhibition, irritability/lability, aberrant motor behavior, appetite/eating, and sleep. Each symptom score derived by frequency of symptoms \* severity of symptoms (range 0-12). Total score = sum of symptom scores; range: 0-144 with higher score indicating greater behavioral disturbances.
Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 1	Week 1	Assessment of the cognitive domain psychomotor function through yes or no responses within 5 minutes to 30 trials; score range: 0 to 3.69. Performance variable: speed of performance; average of the log10 t transformed reaction time for correct responses. Reaction times longer than 5 seconds (log10 \[5000\]) were excluded as reflecting responses that were abnormally slow.
Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 3	Week 3	Assessment of the cognitive domain psychomotor function through yes or no responses within 5 minutes to 30 trials; score range: 0 to 3.69. Performance variable: speed of performance; average of the log10 t transformed reaction time for correct responses. Reaction times longer than 5 seconds (log10 \[5000\]) were excluded as reflecting responses that were abnormally slow.
Computerized Test Battery for Cognition (CogState) Tasks: Detection at Week 6	Week 6	Assessment of the cognitive domain psychomotor function through yes or no responses within 5 minutes to 30 trials; score range: 0 to 3.69. Performance variable: speed of performance; average of the log10 t transformed reaction time for correct responses. Reaction times longer than 5 seconds (log10 \[5000\]) were excluded as reflecting responses that were abnormally slow.
Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 1	Week 1	Assessment of the cognitive domain visual episodic memory (associate learning) through responses within 7 minutes to 4 targets x 4 rounds (mild AD) or 3 targets x 4 rounds (moderate AD); score range: 35 to 100. Performance variable: number of errors made in correctly placing each of the 4 patterns in their location four times.
Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 3	Week 3	Assessment of the cognitive domain visual episodic memory (associate learning) through responses within 7 minutes to 4 targets x 4 rounds (mild AD) or 3 targets x 4 rounds (moderate AD); score range: 35 to 100. Performance variable: number of errors made in correctly placing each of the 4 patterns in their location four times.
Computerized Test Battery for Cognition (CogState) Tasks: Continuous Paired Associate Learning (CPAL) at Week 6	Week 6	Assessment of the cognitive domain visual episodic memory (associate learning) through responses within 7 minutes to 4 targets x 4 rounds (mild AD) or 3 targets x 4 rounds (moderate AD); score range: 35 to 100. Performance variable: number of errors made in correctly placing each of the 4 patterns in their location four times.
Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 1	Week 1	Assessment of the cognitive domain working memory through yes or no responses to 30 trials within 5 minutes; score range: 0 to 1.57. Performance variable: accuracy of performance; arcsine transformation of proportion correct responses.
Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 3	Week 3	Assessment of the cognitive domain working memory through yes or no responses to 30 trials within 5 minutes; score range: 0 to 1.57. Performance variable: accuracy of performance; arcsine transformation of proportion correct responses.
Computerized Test Battery for Cognition (CogState) Tasks: One Back Working Memory at Week 6	Week 6	Assessment of the cognitive domain working memory through yes or no responses to 30 trials within 5 minutes; score range: 0 to 1.57. Performance variable: accuracy of performance; arcsine transformation of proportion correct responses.
Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 1	Week 1	Assessment of the cognitive domain episodic memory through yes or no responses within 5 minutes to 4 targets repeated among 6 distractors on 4 rounds (mild Alzheimer's disease \[AD\], or 3 targets repeated among 4 distractors on 4 rounds (moderate AD) ; score range: 0 to 1.57. Performance variable: accuracy of performance; arcsine transformation of proportion correct responses.
Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 3	Week 3	Assessment of the cognitive domain episodic memory through yes or no responses within 5 minutes to 4 targets repeated among 6 distractors on 4 rounds (mild Alzheimer's disease \[AD\], or 3 targets repeated among 4 distractors on 4 rounds (moderate AD) ; score range: 0 to 1.57. Performance variable: accuracy of performance; arcsine transformation of proportion correct responses.
Computerized Test Battery for Cognition (CogState) Tasks: Visual Learning at Week 6	Week 6	Assessment of the cognitive domain episodic memory through yes or no responses within 5 minutes to 4 targets repeated among 6 distractors on 4 rounds (mild Alzheimer's disease \[AD\], or 3 targets repeated among 4 distractors on 4 rounds (moderate AD) ; score range: 0 to 1.57. Performance variable: accuracy of performance; arcsine transformation of proportion correct responses.
Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 1	Week 1	Assessment of the cognitive domain visual attention through a yes or no response to 30 trials within 5 minutes; score range: 0 to 3.69. Performance variable: speed of performance; average log10 transformed reaction time for correct responses. Reaction times longer than 5 seconds ( log10 \[5000\]) were excluded as reflecting responses that were abnormally slow.
Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 3	Week 3	Assessment of the cognitive domain visual attention through a yes or no response to 30 trials within 5 minutes; score range: 0 to 3.69. Performance variable: speed of performance; average log10 transformed reaction time for correct responses. Reaction times longer than 5 seconds ( log10 \[5000\]) were excluded as reflecting responses that were abnormally slow.
Computerized Test Battery for Cognition (CogState) Tasks: Identification at Week 6	Week 6	Assessment of the cognitive domain visual attention through a yes or no response to 30 trials within 5 minutes; score range: 0 to 3.69. Performance variable: speed of performance; average log10 transformed reaction time for correct responses. Reaction times longer than 5 seconds ( log10 \[5000\]) were excluded as reflecting responses that were abnormally slow.