A Study to Evaluate the Safety and Efficacy of Ustekinumab in Patients With Moderately to Severely Active Crohn's Disease Who Have Failed or Are Intolerant to Tumor Necrosis Factor (TNF) Antagonist Therapy (UNITI-1)

This study (UNITI-1) will compare the effects (both positive and negative) of an initial treatment with ustekinumab to placebo over 8 weeks, in patients with moderately to severely active Crohn's disease who have either failed or could not tolerate at least one TNF-antagonist medications in the past (specifically, infliximab, adalimumab, or certolizumab pegol).