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12 Week Evaluation of the Safety and Efficacy of 3 Doses of CP-526,555 and Placebo for Smoking Cessation

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: August 31, 2005
Last Update Posted: June 4, 2007
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
The purpose of the study is to examine the safety and efficacy and dose-response relationship of three doses of CP-526,555 for 12 weeks compared with placebo for smoking cessation; including post-treatment follow-up of smoking status to one year from randomization. A small satellite protocol (A3051048) investigated safety of a second course of therapy in subjects who did not quit.

Condition Intervention Phase
Smoking Cessation Drug: CP-526,555 (varenicline) Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: A Double-Blind, Placebo-Controlled, Randomized, Multicenter Study Evaluating The Efficacy And Safety Of CP-526,555 In Smokers Motivated To Stop Smoking

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome Measures:
  • 4-week continuous quit rate (CQR) for Weeks 9-12

Secondary Outcome Measures:
  • Continuous abstinence for Weeks 9-52 and Weeks 9-24
  • Long-term quit rate at Week 52
  • 4-week CQR for Weeks 4-7
  • 7-day point prevalence of asbtinence Weeks 12, Week 24, and Week 52
  • Continuous abstinence from TQD (Week 1) through Week 12
  • Weekly average number of cigarettes smoked per day for Weeks 1-12
  • Evaluation of withdrawal symptoms by the Minnesota Nicotine Withdrawal Scale
  • Evaluation of smoking satisfaction by the Smoking Effects Inventory
  • Evaluation of urge to smoke by the Brief Questionnaire of Smoking Urges

Estimated Enrollment: 600
Study Start Date: December 2004
Study Completion Date: February 2006

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Cigarette smokers who are motivated to stop smoking and have smoked an average of at least 10 cigarettes per day

Exclusion Criteria:

  • Subjects who have used a nicotine replacement product within 30 days of the study screening visit or intend to use it during the study.
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00139750

Pfizer Investigational Site
Noda, Chiba, Japan
Pfizer Investigational Site
Sapporo, Hokkaido, Japan
Pfizer Investigational Site
Yokohama, Kanagawa, Japan
Pfizer Investigational Site
Beppu-shi, Oita-ken, Japan
Pfizer Investigational Site
Toyonaka, Osaka, Japan
Pfizer Investigational Site
Tosu, Saga, Japan
Pfizer Investigational Site
Hamamatsu, Shizuoka, Japan
Pfizer Investigational Site
Edogawa-ku, Tokyo, Japan
Pfizer Investigational Site
Minato-ku, Tokyo, Japan
Pfizer Investigational Site
Musashino, Tokyo, Japan
Pfizer Investigational Site
Setagaya-ku, Tokyo, Japan
Pfizer Investigational Site
Shinagawa-ku, Tokyo, Japan
Pfizer Investigational Site
Toshima-ku, Tokyo, Japan
Pfizer Investigational Site
Fukuoka, Japan
Pfizer Investigational Site
Ohita, Japan
Sponsors and Collaborators
Study Director: Pfizer CT.gov Call Center Pfizer
  More Information

Additional Information:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
ClinicalTrials.gov Identifier: NCT00139750     History of Changes
Other Study ID Numbers: A3051046
First Submitted: August 29, 2005
First Posted: August 31, 2005
Last Update Posted: June 4, 2007
Last Verified: June 2007

Additional relevant MeSH terms:
Nicotinic Agonists
Cholinergic Agonists
Cholinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs