A Study To Evaluate The Efficacy And Safety Of Varenicline Compared To Placebo For Smoking Cessation Through Reduction

This study has been completed.
Information provided by (Responsible Party):
ClinicalTrials.gov Identifier:
First received: June 8, 2011
Last updated: September 17, 2013
Last verified: September 2013

This study will determine whether varenicline is safe and helps people to quit smoking through reduction when they are not willing/able to make an abrupt quit attempt.

Condition Intervention Phase
Smoking Cessation
Drug: Varenicline Tartrate
Drug: Placebo
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Health Services Research
Official Title: A Phase 4, Multi-National, Randomized, Double-Blind, Placebo-Controlled Study To Evaluate The Efficacy And Safety Of Varenicline Compared To Placebo For Smoking Cessation Through Reduction

Resource links provided by NLM:

Further study details as provided by Pfizer:

Primary Outcome Measures:
  • Carbon Monoxide (CO) confirmed Continuous Abstinence (CA) during the last 10 weeks of treatment Weeks 15-24 [ Time Frame: Weeks 15-24 ] [ Designated as safety issue: No ]
    abstinence from smoking Weeks 15-24 confirmed by CO < 10

Secondary Outcome Measures:
  • Carbon Monoxide (CO) confirmed Continuous Abstinence (CA) Weeks 21-24 [ Time Frame: Weeks 21-24 ] [ Designated as safety issue: No ]
    abstinence from smoking Weeks 21-24 confirmed by CO < 10

  • Carbon Monoxide (CO) confirmed Continuous Abstinence (CA) Weeks 21-52 [ Time Frame: Weeks 21-52 ] [ Designated as safety issue: No ]
  • 7 day point prevalence of smoking cessation at Weeks 12, 24, and 52 [ Time Frame: Weeks 12, 24, and 52 ] [ Designated as safety issue: No ]
  • 4 week point prevalence of smoking cessation at Week 52 [ Time Frame: Week 52 ] [ Designated as safety issue: No ]

Enrollment: 1494
Study Start Date: July 2011
Study Completion Date: July 2013
Primary Completion Date: July 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Varenicline Tartrate Drug: Varenicline Tartrate
Varenicline Tartrate oral tablets 2 (0.5mg) tablets twice a day for 24 weeks (first week titration)
Placebo Comparator: Placebo Drug: Placebo
Matching placebo 2 oral tablets twice a day for 24 weeks (first week titration)


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Male and female cigarette smokers over the age of 18 years who are not willing/able to quit smoking within the next month but who are willing to attempt to reduce their smoking to work toward a quit attempt within the next 3 months.
  • Subjects must have smoked an average of at least 10 cigarettes per day during the past year and during the month prior to the screening visit, with no continuous period of abstinence greater than 3 months in the past year and who have an exhaled carbon monoxide (CO) >10 ppm at screening.
  • Subjects with mild to moderate depression or anxiety may be included if their condition is stable.

Exclusion Criteria:

  • Subjects with a history of a suicide attempt or any suicidal behavior in the past two years.
  • Subjects with severe depression or anxiety.
  • Subjects with psychosis, panic disorder, bipolar disorder, post traumatic stress disorder (PTSD), or schizophrenia.
  • Subjects with alcohol or substance abuse or dependence (except nicotine) unless in full remission for at least 12 months.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01370356

  Show 65 Study Locations
Sponsors and Collaborators
Study Director: Pfizer CT.gov Call Center Pfizer
  More Information

Additional Information:
No publications provided

Responsible Party: Pfizer
ClinicalTrials.gov Identifier: NCT01370356     History of Changes
Other Study ID Numbers: A3051075, REDUCE TO QUIT
Study First Received: June 8, 2011
Last Updated: September 17, 2013
Health Authority: United States: Food and Drug Administration

Keywords provided by Pfizer:
smoking reduction
smoking cessation

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

ClinicalTrials.gov processed this record on August 27, 2014