A Phase 3, Randomized, Double-blind, Placebo-controlled, Parallel-group, Multicenter Study to Evaluate the Safety and Efficacy of Ustekinumab Induction Therapy in Subjects With Moderately to Severely Active Crohn's Disease Who Have Failed or Are Intolerant to 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).