A multicenter, randomized, double-blind, placebo controlled, parallel group study of eszopiclone 3 mg in subjects with insomnia related to rheumatoid arthritis. 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.