Randomized Study Comparing the Efficacy and Safety of Varenicline Tartrate to Placebo in Smoking Cessation When Subjects Are Allowed to Set Their Own Quit Date

Percentage of Participants With Continuous Abstinence (CA) From Smoking Weeks 9-24

Percentage of participants with CA from cigarette smoking and other nicotine-containing (treatment phase) or tobacco (non-treatment phase) products use, who did not have CO \>10 ppm at any visits Week 9 through Week 24. A participant was considered a responder if they met the following criterion: said they had not smoked or used nicotine products 'since the last visit' and did not have CO \>10 ppm.

Time frame: Week 9 through Week 24

Percentage of Participants With Long Term Quit Through Week 24

Responder for the primary endpoint of CA from Week 9 through Week 12 and who had no more than 6 days of smoking during the non-treatment phase of the study. For Weeks 13, 16, 20, and 24, long term quit was determined by CO-confirmed in-clinic visit.

Time frame: Week 9 through Week 24

Percentage of Participants With 7-day Point Prevalence of Nonsmoking (Smoking Cessation)

Percentage of participants with complete abstinence from cigarette smoking or other nicotine-containing (treatment phase) or tobacco (non-treatment phase) products use for the 7 days prior to Week 12 and Week 24, respectively, who did not have CO \>10 ppm at any visits. CO-confirmed in-clinic visit.

Time frame: Week 12 and Week 24

Percentage of Participants With 4-week Point Prevalence of Nonsmoking