A Seven-Week Dose-Ranging Study of CP-526,555 Compared With Placebo and Zyban for Smoking Cessation

A Seven-Week Double-Blind, Placebo-Controlled, Randomized, Multicenter Study Evaluating the Safety and Efficacy of Three Doses of CP-526,555 ( 0.3 mg QD, 1 mg QD, and 1 mg BID ) in Comparison With Zyban in Smoking Cessation

The purpose of the study is to measure the safety and efficacy of three doses of varenicline for smoking cessation.

Inclusion Criteria:

• Subjects must have smoked on average of at least ten cigarettes per day during the past year
• Subjects must have no period of abstinence greater than three months in the past year

Exclusion Criteria:

• Subjects with any history of cardiovascular disease
• Myocardial infarction
• Significant arrhythmias
• Poorly controlled hypertension