Study Evaluating The Efficacy Of Varenicline In Cessation Of Oral Smokeless Tobacco Use

Inclusion Criteria: * Male or female daily smokeless tobacco users aged 18 years and older, who are motivated to stop use of all tobacco products. * Subjects must be daily users of nicotine containing smokeless tobacco and using smokeless tobacco on at least 8 occasions per day averaged over a week. * Have used smokeless tobacco for at least 1 year prior to screening with no period of abstinence \>3 months in the past year. Exclusion Criteria: * Subjects using nicotine containing products (including smoking tobacco) other than smokeless tobacco for 3 months prior to screening. * Subjects with exhaled Carbon Monoxide (CO) \>10 ppm at baseline. * Subjects who have used varenicline, bupropion, or NRT within 3 months of screening. * Subjects currently or within the past 12 months requiring treatment for depression or have a current or prior history of panic disorder, psychosis, bipolar disorder or any other serious mental illness.