A Phase 2b, Multicenter, Randomized, Double-Blind, Placebo controlled, Parallel-group Study to Evaluate the Efficacy and Safety of Ustekinumab Therapy in Subjects with Moderately to Severely Active Crohn’s Disease Previously Treated with TNF Antagonist Therapy

The purpose of this study is to determine whether or not treatment with an experimental drug called Ustekinumab and whether or not the treatment will reduce the symptoms of Crohn's disease in adult patients who have moderate to severe Crohn's disease.

You may be eligible for this study if you meet the following criteria:

• Are at least 18 years of age or older
• Have had Crohn's disease for at least 3 months
• Have received previous treatment that did not work

Participants will need to be able to adhere to the study visit schedule and other protocol requirements.