Relapse Prevention Study in Newly Abstinent Smokers

GSK598809 once daily for 12 weeks

All subjects will be treated during the 4 week open-label smoking cessation phase of the study. During Weeks 1-3, subjects will receive 21mg/day, and during Week 4, subjects will receive 14 mg/day. Those subjects who reached continuous abstinence on at least week 4 of the open-label phase will receive 7mg/day during Week 5 while taking GSK598809 or placebo.

Placebo once daily for 12 weeks