A Study to Investigate the Efficacy and Safety of GSK1605786A in the Treatment of Subjects With Moderately-to-Severely Active Crohn's Disease

This is a randomised, double-blind, placebo-controlled study to evaluate the efficacy and safety of two doses (500 mg once daily and 500 mg twice daily) of GSK1605786A as compared to placebo over 12 weeks in adult subjects with moderately-to-severely active Crohn's disease. Efficacy will be assessed by proportion of subjects achieving response, defined as a decrease in Crohn's Disease Activity Index (CDAI) score of at least 100 points (clinical response). Clinical remission (CDAI score less than 150 points) will be evaluated as a key secondary endpoint. Safety will be assessed by recording of adverse events, clinical laboratory parameters, vital signs and electrocardiogram (ECG). Population pharmacokinetics will evaluate the two doses of GSK1605786A. Health outcomes assessments will include changes in Inflammatory Bowel Disease Questionnaire (IBDQ), Short Form-36 version 2 (SF-36v2), EQ-5D and Work Productivity and Activity Impairment-CD (WPAI-CD) and receipt of disability.