This was a Phase III, double-blind, randomized, placebo- and active-controlled, multicenter, parallel-group study of up to 6 weeks in duration. Seven days of QID single-blind, placebo administration (via HFA MDI) was followed by 28 days of QID, double-blind treatment. A follow-up visit was required only for subjects who had, in the opinion of the investigator, a clinically significant finding at Visit 6 /ET that would put the subject at risk. A final follow up phone evaluation was conducted 7 days after the completion of Visit 6/ET. This study was previously posted by Sepracor Inc. In October 2009, Sepracor Inc. was acquired by Dainippon Sumitomo Pharma., and in October 2010, Sepracor Inc's name was changed to Sunovion Pharmaceuticals Inc.