A Multi-National Study To Assess How Effective And Safe The Smoking Cessation Medicine Varenicline Is In Smokers Who Have Already Tried Varenicline In The Past As A Prescription Medicine From Their Usual Healthcare Provider

Study Overview
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Brief Summary
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The main purpose of this study is to compare the effectiveness and safety of the re-treatment of smokers with varenicline with placebo for smoking cessation during the last 4 weeks of a 12 week course of treatment. The study will also assess whether smokers remain abstinent at Week 24 (12 weeks after the end of treatment) and Week 52 (40 weeks after the end of treatment).

Official Title
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A Phase 4 Randomized, Double-Blind, Placebo-Controlled, Multicenter Study Evaluating The Efficacy And Safety Of Re-Treatment With Varenicline In Subjects Who Are Currently Smoking, And Who Have Previously Taken Varenicline

Conditions
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Smoking Cessation

Intervention / Treatment
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* Drug: Varenicline
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Smokers aged 18 years or above and wanting to stop smoking Smokers who have smoked an average of at least 10 cigarettes per day over the last 4 weeks Smokers who have tried before to stop smoking at least once with varenicline, and who took varenicline for at least 2 weeks The last attempt to stop smoking must be at least 3 months before entering the study Exclusion Criteria: Individuals who have not tolerated varenicline well previously, or who have a current or prior medical or psychiatric history that would make entry into the trial inadvisable Individuals who have previously participated in clinical trials of varenicline Individuals who have been participating in another smoking cessation trial within the last 3 months, or other drug trial within the last 30 days

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Varenicline<br> | Drug: Varenicline<br>* Varenicline 1mg twice daily<br>|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* Matched placebo twice daily<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Continuous Abstinence Rate (CAR) From Week 9 Through Week 12 | The percentage of participants who, from Week 9 through Week 12, reported no smoking and no use of other nicotine-containing products since the last study visit/last contact (on the Nicotine Use Inventory) and who did not have carbon monoxide (CO)> 10ppm at any visits during this time frame. | Week 9 through Week 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CAR From Week 9 Through Week 52 | The percentage of participants who, from Week 9 through Week 52, reported no smoking (Weeks 9 through 52) and no use of other nicotine-containing products (Weeks 9 through 12), or no use of other tobacco products (Weeks 13 through 52), since the last study visit/last contact (on the Nicotine Use Inventory) and who did not have CO >10 ppm at any of these visits during this time frame. | Week 9 through Week 52 | 
| CAR From Week 9 Through Week 24 | The percentage of participants who, from Week 9 through Week 24, reported no smoking (Weeks 9 through 24) and no use of other nicotine-containing products (Weeks 9 through 12), or no use of other tobacco products (Weeks 13 through 24), since the last study visit/last contact (on the Nicotine Use Inventory) and who did not have CO >10 ppm at any of these visits during this time frame. | Week 9 through Week 24 | 
| 7-day Point Prevalence (PP) of Abstinence at Weeks 12, 24, and 52 | The secondary endpoint of 7-day point prevalence of smoking cessation was determined by evaluating a participant's cigarette smoking status, and other nicotine (and/or other tobacco) use, based on the last 7 days questions in the Nicotine Use Inventory. Additionally, a participant was not considered a responder if the expired CO was >10 ppm at the time point being summarized. Participants were considered responders independently at each visit. | Weeks 12, 24 and 52 |