The purpose of this study is to assess the safety and efficacy of AFQ056 and nicotine compared to placebo on craving and withdrawal symptoms during voluntary smoking stoppage in healthy smokers. This study will also assess how the body interacts with AFQ056.

Inclusion Criteria:

• Healthy, male & female subjects at least 18 years and ≤60 years of age
• In good health
• Female subjects must be surgically sterilized or postmenopausal.
• Current smokers not intending to quit
• Smoke on average 15 cigarettes or more and less than 60 cigarettes a day for the past year
• Fagerström Test for Nicotine Dependence score of at least 5 (indicates moderate to heavy smokers)
• Willing to refrain from smoking as required
• Written informed consent before entering the study

Exclusion Criteria:

• History of heart disease, septum defect and/or cardiac valves surgery; clinical relevant abnormality in the ECG
• Investigational drug treatment within 4 weeks prior to screening unless local health authority guidelines mandate a longer period
• Women of childbearing potential, pregnant or lactating females
• Donation of one unit (400mL) or more of blood, significant blood loss equaling at least one unit of blood within the past 2 months or a blood transfusion within 8 weeks prior to screening.
• Coffee consumption of more than 6 cups coffee/day
• Use of a medication within 2 weeks prior to Day 1 of each treatment period

Other protocol-defined inclusion/exclusion criteria may apply