Vigabatrin for Treatment of Cocaine Dependence

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Catalyst Pharmaceutical Partners, Inc
ClinicalTrials.gov Identifier:
NCT00611130
First received: January 28, 2008
Last updated: May 10, 2012
Last verified: May 2012
Results First Received: April 13, 2012  
Study Type: Interventional
Study Design: Allocation: Randomized;   Endpoint Classification: Safety/Efficacy Study;   Intervention Model: Parallel Assignment;   Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor);   Primary Purpose: Treatment
Condition: Cocaine Dependence
Interventions: Drug: vigabatrin
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
01/08-01/09 at 11 US research trial sites.

Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
After Informed Consent obtained, subjects entered a 2-4 week Screening/Baseline Phase to determine whether all Inclusion/Exclusion Criteria were met. Randomization strata included gender, primary method of cocaine administration (snort or intravenous/smoke) & use in last 30 days (≤18 days or >18 days)

Reporting Groups
  Description
CPP-109 Vigabatrin CPP-109 tablets, 500 mg. 3 Tablets bid.
Placebo Matching Placebo Tablets. 3 tablets bid.

Participant Flow:   Overall Study
    CPP-109 Vigabatrin     Placebo  
STARTED     92     94  
Completed 12 Week Treatment Phase     61     64  
COMPLETED     43     47  
NOT COMPLETED     49     47  
Lost to Follow-up                 25                 29  
Protocol noncompliance                 7                 6  
Withdrawal by Subject                 6                 5  
Unspecified                 5                 4  
Incarceration                 3                 2  
Administrative                 1                 1  
Adverse Event                 1                 0  
Death                 1                 0  



  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
CPP-109 Vigabatrin CPP-109 tablets, 500 mg. 3 Tablets bid.
Placebo Matching Placebo Tablets. 3 tablets bid.
Total Total of all reporting groups

Baseline Measures
    CPP-109 Vigabatrin     Placebo     Total  
Number of Participants  
[units: participants]
  92     94     186  
Age  
[units: years]
Mean ± Standard Deviation
  44.6  ± 7.62     45.0  ± 8.33     44.8  ± 7.92  
Gender  
[units: participants]
     
Female     32     30     62  
Male     60     64     124  
Region of Enrollment  
[units: participants]
     
United States     92     94     186  



  Outcome Measures
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1.  Primary:   Proportion of Subjects in Each Treatment Group Abstinent During the Last 2 Weeks of Treatment.   [ Time Frame: Week 13 ]

Measure Type Primary
Measure Title Proportion of Subjects in Each Treatment Group Abstinent During the Last 2 Weeks of Treatment.
Measure Description Number of subjects in the CPP-109 Vigabatrin Group vs. Number in Placebo Group abstinent from using cocaine during Weeks 11 and 12 of the Treatment Phase.
Time Frame Week 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.
intent-to-treat

Reporting Groups
  Description
CPP-109 Vigabatrin Tablets, 500 mg Vigabatrin Tablets, 1.5 g bid po, 12 weeks, computerized cognitive behavioral therapy plus contingency management.Subjects proceeded to a 12 week Treatment Phase, including a 2 week dose escalation period, a 9 week maintenance period (3.0 gm/day of vigabatrin) and a 1 week medication taper period. Finally, subjects then proceeded to a 12 week follow-up period. Subjects attended clinic visits 3 times per week (typically on Monday, Wednesday, and Friday) for efficacy and safety assessments and for treatment during the Screening/Baseline Phase and the 12 week Treatment Phase. Subjects returned for follow up visits at Weeks 13, 16, 20 and 24.
Matching Placebo Tablets Subjects proceeded to a 12 week Treatment Phase,receiving 3 tablets bid po Finally, subjects then proceeded to a 12 week follow-up period. Subjects attended clinic visits 3 times per week (typically on Monday, Wednesday, and Friday) during the Screening/Baseline Phase and the 12 week Treatment Phase. Subjects returned for follow up visits at Weeks 13, 16, 20 and 24.

Measured Values
    CPP-109 Vigabatrin Tablets, 500 mg     Matching Placebo Tablets  
Number of Participants Analyzed  
[units: participants]
  92     94  
Proportion of Subjects in Each Treatment Group Abstinent During the Last 2 Weeks of Treatment.  
[units: participants]
  7     5  

No statistical analysis provided for Proportion of Subjects in Each Treatment Group Abstinent During the Last 2 Weeks of Treatment.



2.  Post-Hoc:   Medication Compliance   [ Time Frame: Week 2, 4, 6 & 9-11 ]

Measure Type Post-Hoc
Measure Title Medication Compliance
Measure Description Using retained urine samples and prior to unblinding, up to 12 specimens/ subject were analyzed for vigabatrin levels. Compliance assessment based on > or = 70% of urines in subjects assigned to vigabatrin having quantitative levels of vigabatrin indicaticative of taking drug within the last 24 hours of clinic visit.
Time Frame Week 2, 4, 6 & 9-11  
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.
Completers were defined as those who attended the scheduled Week 13 visit or the third visit of Week 12 and who also had provided urines during Weeks 11 & 12.

Reporting Groups
  Description
Treatment Phase Completers Up to 12 urine specimens out of 37 collected during the Treatment Phase completers were analyzed for vigabatrin levels.

Measured Values
    Treatment Phase Completers  
Number of Participants Analyzed  
[units: participants]
  125  
Medication Compliance  
[units: participants]
 
Number of Vigabatrin Completers Analyzed     61  
Number Medication Compliant     24  

No statistical analysis provided for Medication Compliance




  Serious Adverse Events


  Other Adverse Events


  Limitations and Caveats
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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
Lack of subject medication compliance, site-to-site variability in medication compliance possibly indicative of differing site capabilities to attract subjects sufficiently motivated to stop using cocaine.


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