Effectiveness of GW468816, an NMDA Glycine Site Antagonist, for Prevention of Relapse to Smoking

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. Identifier: NCT00218465
Recruitment Status : Completed
First Posted : September 22, 2005
Results First Posted : December 20, 2010
Last Update Posted : March 24, 2017
National Institute on Drug Abuse (NIDA)
Mclean Hospital
Information provided by (Responsible Party):
Maurizio Fava, MD, Massachusetts General Hospital

Brief Summary:

The purpose of this study is to evaluate the efficacy of the glycine antagonist, GW468816, compared with placebo on duration of abstinence and rates of relapse in recently quit female smokers in a randomized, double-blind, five-week clinical trial.

According to the investigators, the new medication, GW468816, is thought to send certain signals in the brain that may be effective in helping people stay abstinent after they have recently quit smoking. GW468816 is a non-nicotine drug.

The investigators of this study hypothesize that subjects receiving GW468816 will demonstrate a significantly longer time to relapse to smoking than those in the placebo group, as measured by the primary outcome measure (see below).

Condition or disease Intervention/treatment Phase
Nicotine Dependence Drug: GW468816 Drug: Placebo Comparator: Placebo Phase 2

Detailed Description:

Smoking is the leading cause of preventable mortality in developed countries. Pharmacotherapy, including bupropion and nicotine replacement therapy (NRT), is universally recommended for smoking cessation treatment; however, even with treatment, the majority of smokers either fail to quit in the short term or relapse in the first year. The high failure rate reported for smoking cessation, then, presents a challenge to explore innovative approaches to treating relapse to smoking.

The purpose of this study, then, is to evaluate the efficacy of the glycine antagonist, GW468816, compared with placebo on duration of abstinence and rates of relapse in female outpatient smokers during a randomized, double-blind, five-week clinical trial.

To do this, the investigators will conduct a two-phase study, in which 300 adult, female outpatient smokers will be enrolled.

Phase I will consist of an 8-week smoking cessation study in which nicotine replacement therapy (NRT) and a behavioral intervention are openly administered on a tapered schedule. Participants who are able to quit smoking after 7 weeks in this preliminary study will then be eligible to enter Phase II.

Phase II is a 5-week, double-blind, placebo-controlled, relapse prevention trial with the investigational medication, GW468816.

Participants in the Phase I smoking cessation study will begin by receiving nicotine replacement therapy in the form of the patch and brief support to stop smoking. Participants will be required to schedule office visits every 1-2 weeks throughout Phase I.

Subjects who are abstinent at the end of Phase I will be eligible to continue Phase II, in which they will be randomly assigned by chance to receive the investigational medication, GW468816, at 200 mg or placebo (a pill that looks exactly like the study drug but contains no active drug). Participants will be required to schedule weekly office visits throughout Phase II.

Subjects who complete the 15-week trial (both Phases I and II) will enter the 6-Month Follow-Up to evaluate rates of long term abstinence from nicotine. They will have office visits at Weeks 20, 24, 28, 32, 36, and 40 after discontinuation of study medications.

Participants who enter the study will be offered the opportunity to participate in an ancillary neuroimaging study of mechanisms and surrogate markers of relapse that includes BOLD fMRI and MR spectroscopy, to be carried out at the McLean Brain Imaging Center.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 264 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: A Double-Blind, Placebo-Controlled Trial of the NMDA Glycine Site Antagonist, GW468816, for Prevention of Relapse to Smoking
Study Start Date : August 2006
Actual Primary Completion Date : June 2009
Actual Study Completion Date : June 2009

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Smoking
Drug Information available for: Glycine

Arm Intervention/treatment
Experimental: GW468816
Glycine Antagonist GW468816, 200 mg/day, for a 5-week trial
Drug: GW468816
Pharmacotherapies for Relapse Prevention
Other Name: GW468816: NMDA glycine-site antagonist

Placebo Comparator: Placebo
Placebo, 200 mg/day, for a 5-week trial
Drug: Placebo Comparator: Placebo

Primary Outcome Measures :
  1. Time to Relapse to Smoking in the 5-week Relapse Prevention Phase. [ Time Frame: 5 weeks ]
  2. Number of Abstinent and Nonabstinent Participants at End of 5 Week Placebo-controlled Relapse Prevention Trial [ Time Frame: 5 weeks ]
  3. Days to Relapse Within the 60 Days Following Randomization [ Time Frame: 60 days ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Written informed consent
  2. WOMEN aged 18-65 years, inclusive
  3. Self-report of smoking 10 or more cigarettes per day in the past 6 months and expired air CO >10 ppm at the time of enrollment
  4. DSM-IV criteria for current Nicotine Dependence satisfied
  5. Subjects must be willing to take the study medication and be motivated to quit smoking (willing to set a quit date within 2 weeks of entry into the protocol)
  6. Women of childbearing potential must have a negative urine pregnancy test (quantitative HCG) at baseline and at week 8, prior to receiving the first dose of study medication and females must agree to use an approved form of contraception from the day of the first dose of study medication for 90 days after the last dose of study medication. Approved forms of contraception include any of the following:

    • Complete abstinence from intercourse from 2 weeks prior to administration of the study drug, through the treatment phase and for 90 days after discontinuation of study medication.
    • Sterilization of male partner
    • Implant of levonorgestrel
    • Injectable progesterone
    • Intrauterine device (IUD) with <1 percent rate of failure per year
    • Any other method with published rate of failure of <1 percent per year Due to induction of cytochrome p450 3A4, oral contraceptives may be continued during the study but cannot be relied upon as a sole means of contraception, and a second method of contraception such as a barrier method will be required and reimbursed by the study.

Exclusion Criteria:

  1. Pregnant or able to become pregnant and not willing to use approved contraception
  2. Severe unstable medical illness including cardiovascular, hepatic, renal, respiratory, metabolic, neurological, or hematological disease by history, physical examination or clinical laboratory test results such that hospitalization for treatment of that illness is likely within the next two months
  3. Life-threatening arrhythmia, cerebro-vascular or cardiovascular event within six months of enrollment
  4. Elevation over 1.5 times upper limit of normal value (ULN) of any of the following laboratory results: Total, conjugated, or unconjugated bilirubin; alkaline phosphatase, alanine transferase (ALT), aspartate aminotransferase (AST), creatine phosphokinase (CPK), or lactate dehydrogenase (LDH).
  5. Use of tobacco-containing products other than cigarettes (e.g., cigar, pipe)
  6. Abuse or dependence of any substance other than nicotine or caffeine in the past 6 months. Abuse of alcohol is here defined as an average weekly intake of greater than 21 units or an average daily intake of greater than three units (males) or defined as an average weekly intake of greater than 14 units or an average daily intake of greater than two units (females). One unit is equivalent to a half-pint (220mL) of beer or one (25mL) measure of spirits or one glass (125mL) of wine.
  7. Diagnosis of major depressive disorder in the past 6 months
  8. Lifetime DSM-IV diagnosis of organic mental disorder, schizophrenia, schizoaffective disorder, bipolar disorder, delusional disorder or psychotic disorders not elsewhere classified
  9. History of non-response in the past month to an adequate trial of nicotine re placement therapy, defined as nicotine replacement > 21 mg per day patch (or equivalent dose of gum, inhaler, nasal spray, or lozenge) for at least 4 weeks.
  10. History of multiple adverse drug reactions
  11. Use of an investigational drug or device within 4 weeks of enrollment
  12. Concurrently enrolled in a study that involves exposure to a drug or device.
  13. Urine positive for drugs of abuse at screening visit.
  14. Use of statins during the period of the investigation.

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 identifier (NCT number): NCT00218465

United States, Massachusetts
McLean Hospital, Brain Imaging Center
Belmont, Massachusetts, United States, 02478 9106
Massachusetts General Hospital
Boston, Massachusetts, United States, 02114
Sponsors and Collaborators
Massachusetts General Hospital
National Institute on Drug Abuse (NIDA)
Mclean Hospital
Principal Investigator: Maurizio Fava, M.D. Massachusetts General Hospital
Principal Investigator: Eden Evins, M.D., M.P.H. Massachusetts General Hospital

Responsible Party: Maurizio Fava, MD, Maurizio Fava, M.D., Massachusetts General Hospital Identifier: NCT00218465     History of Changes
Other Study ID Numbers: NIDA-19378-2
U01DA019378 ( U.S. NIH Grant/Contract )
IND 74964 ( Other Identifier: IND Number )
First Posted: September 22, 2005    Key Record Dates
Results First Posted: December 20, 2010
Last Update Posted: March 24, 2017
Last Verified: March 2017

Keywords provided by Maurizio Fava, MD, Massachusetts General Hospital:
Drugs, Investigational
Therapies for Relapse to Nicotine
Relapse Prevention
Nicotine Cessation Therapies
Smoking Cessation
Nicotine Dependence

Additional relevant MeSH terms:
Tobacco Use Disorder
Disease Attributes
Pathologic Processes
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Ganglionic Stimulants
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Nicotinic Agonists
Cholinergic Agonists
Cholinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Glycine Agents