Effects of Varenicline on Brain Activity During Nicotine Abstinence

This study has been completed.
Sponsor:
Collaborators:
Pfizer
Information provided by:
University of Pennsylvania
ClinicalTrials.gov Identifier:
NCT00602927
First received: January 15, 2008
Last updated: May 6, 2011
Last verified: May 2011
Results First Received: October 6, 2010  
Study Type: Interventional
Study Design: Allocation: Randomized;   Endpoint Classification: Efficacy Study;   Intervention Model: Crossover Assignment;   Masking: Double Blind (Subject, Caregiver, Investigator);   Primary Purpose: Treatment
Condition: Nicotine Dependence
Interventions: Drug: Varenicline
Drug: Placebo

  Participant Flow
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Recruitment Details
Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
Participants were recruited from mass media advertising in the greater Philadelphia area from November 2007 - June 2008.

Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
All participants completed a 14 day wash-out period between the two study phases. They were instructed to resume their usual smoking behavior in this wash-out phase.

Reporting Groups
  Description
Placebo First, Then Varenicline Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally
Varenicline First, Then Placebo Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally

Participant Flow for 3 periods

Period 1:   Period 1: 13 Days
    Placebo First, Then Varenicline     Varenicline First, Then Placebo  
STARTED     19     19  
COMPLETED     15     14  
NOT COMPLETED     4     5  
Protocol Violation                 2                 4  
MRI scanner technical issue                 1                 0  
Time                 1                 0  
Claustrophobia                 0                 1  

Period 2:   Period 2: 14 Days
    Placebo First, Then Varenicline     Varenicline First, Then Placebo  
STARTED     15     14  
COMPLETED     15     12  
NOT COMPLETED     0     2  
Protocol Violation                 0                 2  

Period 3:   Period 3: 13 Days
    Placebo First, Then Varenicline     Varenicline First, Then Placebo  
STARTED     15     12  
COMPLETED     13     9  
NOT COMPLETED     2     3  
Protocol Violation                 0                 1  
MRI data quality                 2                 2  



  Baseline Characteristics
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Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
No text entered.

Reporting Groups
  Description
Placebo First, Then Varenicline Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally
Varenicline First, Then Placebo Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally
Total Total of all reporting groups

Baseline Measures
    Placebo First, Then Varenicline     Varenicline First, Then Placebo     Total  
Number of Participants  
[units: participants]
  19     19     38  
Age  
[units: participants]
     
<=18 years     0     0     0  
Between 18 and 65 years     19     19     38  
>=65 years     0     0     0  
Age  
[units: years]
Mean ± Standard Deviation
  41.05  ± 13.32     39.79  ± 12.68     40.42  ± 12.84  
Gender  
[units: participants]
     
Female     9     10     19  
Male     10     9     19  
Region of Enrollment  
[units: participants]
     
United States     19     19     38  



  Outcome Measures
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1.  Primary:   Percent Change BOLD Signal   [ Time Frame: Day 13 ]

Measure Type Primary
Measure Title Percent Change BOLD Signal
Measure Description We calculated the percent BOLD signal change while performing the N-back task between the varenicline vs. placebo session. We subtracted BOLD signal observed during the 0-back condition from the BOLD signal observed during the 3-back condition (3back minus 0-back)We controlled for relevant co-variates such as sex, nicotine dependence level and education.
Time Frame Day 13  
Safety Issue No  

Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
Participants who completed both study phases were included in the analyses (n=25). Additional participants (n=3) were excluded due to measurement artifact.

Reporting Groups
  Description
Placebo Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally
Varenicline Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally

Measured Values
    Placebo     Varenicline  
Number of Participants Analyzed  
[units: participants]
  22     22  
Percent Change BOLD Signal  
[units: BOLD Signal Change (3-back minus 0-back)]
Mean ± Standard Error
  0.48  ± 0.05     0.61  ± 0.03  

No statistical analysis provided for Percent Change BOLD Signal



2.  Secondary:   Effect of Varenicline Treatment on Task Performance (N-back Correct Response Time)   [ Time Frame: Day 13 ]

Measure Type Secondary
Measure Title Effect of Varenicline Treatment on Task Performance (N-back Correct Response Time)
Measure Description We examined the difference in correct reaction time on the N-back task between varenicline and placebo treatment. Models included terms for the main effect of treatment period (varenicline vs. placebo), memory load (0-back, 1-back, 2-back, 3-back) and covariates. We tested for interactions between nicotine dependence severity and treatment.
Time Frame Day 13  
Safety Issue No  

Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate.
Participants who completed both study phases were included in the analysis. Other participants (n=3) were excluded due to measurement artifact.

Reporting Groups
  Description
Placebo Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally
Varenicline Days 1 – 3: 0.5 mg once a day orally Days 4 – 7: 0.5 mg twice a day orally Days 8 – 13: 1 mg twice a day orally

Measured Values
    Placebo     Varenicline  
Number of Participants Analyzed  
[units: participants]
  22     22  
Effect of Varenicline Treatment on Task Performance (N-back Correct Response Time)  
[units: Milliseconds]
Mean ± Standard Deviation
  692.14  ± 128.57     637.99  ± 164.30  

No statistical analysis provided for Effect of Varenicline Treatment on Task Performance (N-back Correct Response Time)




  Serious Adverse Events


  Other Adverse Events


  More Information
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Certain Agreements:  
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.


Limitations and Caveats
Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
No text entered.  


Results Point of Contact:  
Name/Title: Dr. Caryn Lerman
Organization: University of Pennsylvania
phone: 215-746-7141
e-mail: clerman@mail.med.upenn.edu


Publications of Results:

Responsible Party: Dr. Caryn Lerman, University of Pennsylvania
ClinicalTrials.gov Identifier: NCT00602927     History of Changes
Other Study ID Numbers: 806623, GA30517A, P50CA084718
Study First Received: January 15, 2008
Results First Received: October 6, 2010
Last Updated: May 6, 2011
Health Authority: United States: Institutional Review Board