A Phase III, 12-Week, Multicentre, Double-Blind, Randomised, Placebo- and Active Comparator-Controlled, Parallel Group Study to Investigate the Efficacy and Safety of GW406381, 5mg, 10mg, 25mg, and 50mg administered orally once daily, in Adults with Rheumatoid Arthritis - A Phase III, 12-Week, Multicentre, Double-Blind, Randomised, Placebo- and Active Comparator-Controll ...