Efficacy and Safety of Pregabalin vs Placebo for Generalized Anxiety Disorder (GAD) Symptoms in Subjects Discontinuing Benzodiazepine Treatment and Remaining 6 Weeks on Study Medication, Free From Benzodiazepine Use.

Condition(s) targeted: Generalized Anxiety Disorder

Intervention: Pregablin (Drug); Placebo (Other)

Phase: Phase 3

Status: Recruiting

Sponsored by: Pfizer

Official(s) and/or principal investigator(s):
Pfizer CT.gov Call Center, Study Director, Affiliation: Pfizer

Overall contact:
Pfizer CT.gov Call Center, Phone: 1-800-718-1021

GAD subjects maintained on a stable dose of alprazolam for at least four weeks who meet eligibility criteria will be randomized to receive pregabalin vs matching placebo while simultaneously tapering off of alprazolam over 6 weeks. Subjects return weekly for assessment of safety/tolerability of pregablin vs placebo as well as for assessment of anxiety and benzodiazepine withdrawal symptoms. Subjects sucessfully able to discontinue alprazolam, will continue 6 weeks of treatment with pregabalin vs placebo (free of benzodiazepine use). The efficacy and safety of pregablin vs placebo for anxiety symptoms and ability to discontinue/remain free of alprazolam will be compared among pregablin and placebo treated groups. Hypothesis is that a greater proportion of subjects will be successful in discontinuing and remaining free from benzodiazepines who were treated with pregabalin as compared to subjects treated with placebo.

Official title: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study of Pregabalin in Subjects With Generalized Anxiety Disorder (GAD) Switching From Benzodiazepine Therapy.

Study design: Treatment, Randomized, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Parallel Assignment, Safety/Efficacy Study

Primary outcome:

Negative urine benzodiazepine/psychoactive toxicology assay (done at each visit of the Alprazolam-Free Phase of Double-Blind Treatment) and negative serum benzodiazepine/alcohol assay (done at endpoint).

Negative benzodiazepine use defined as negative labs for benzodiazepines as well not requiring use of 'rescue' alprazolam packet between visits

Efficacy/Safety: Following taper and discontinuation from stable benzodiazepine treatment,the proportion of subjects treated with pregabalin who remain 6 weeks free from benzodiazepine use compared to subjects treated with placebo.

Secondary outcome:

Mean change between 'randomization/baseline' score of Clinical Global Impression Severity (CGI-S) and weekly scores of CGI-S.

Proportion of subjects with > 6 point increase in PWC scores compared to baseline or compared to a previous week in the 6 week benzodiazepine free period.

Proportion of subjects with > 5 new PWC symptoms between weekly visits during the benzodiazepine free 6 week period or between a weekly visit and baseline visit.

Amount of time 'relapse free' among treatment groups during 6 week 'benzodiazepine free'phase (Relapse free-defined as negative labs for benzodiazepines and not requiring more than allowed rescue benzodiazepine medication between visits)

Mean 'Patient Global Impression-Improvement' (PGI-I) score at each visit.

Mean Clinician Global Impression-Improvement (CGI-I) score at each visit.

Time until first subject needs to take "rescue medication"

Mean change in weekly 'Physician Withdrawal Checklist' (PWC) scores compared to randomization /baseline

Mean change from randomization /baseline to endpoint in 'Digit Symbol Substitution Test'(DSST) scores

Mean change in weekly anxiety scores compared to baseline (measured by Hamilton Anxiety Scale or HAM-A)

Time until subject discontinuation (inability to tolerate benzodiazepine taper or free state)

Minimum age: 18 Years. Maximum age: 65 Years. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Provide written informed consent

- 18-65 years old

- male and female

- A primary lifetime diagnosis of DSM-IV-TR (2000) GAD (Diagnostic and Statistical

Manual of Mental Disorders, Fourth Edition)

Exclusion Criteria:

- Pregnant or lactating women

- History of non-response to alprazolam, other benzodiazepines, gabapentine or

pregabalin given for the treatment of anxiety as indicated by a (screening or baseline) Hamilton Anxiety Scale (HAM-A) score > 18

Pfizer CT.gov Call Center, Phone: 1-800-718-1021

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Pfizer Investigational Site, L'Aquila 67100, Italy; Active, not recruiting

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Pfizer Investigational Site, San Luis Potosi 78216, Mexico; Active, not recruiting

Pfizer Investigational Site, BARCELONA 08036, Spain; Active, not recruiting

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Pfizer Investigational Site, Paris, Cedex 12 75571, France; Completed

Pfizer Investigational Site, Tepic, Nayarit 63000, Mexico; Active, not recruiting

Pfizer Investigational Site, San Pedro de Montes de Oca, San José 00, Costa Rica; Completed

To obtain contact information for a study center near you, click here.

Starting date: September 2006
Ending date: September 2008
Last updated: October 9, 2008