A Study of the Safety and Efficacy of Ustekinumab (CNTO 1275) in Participants With Crohn's Disease

one 90 mg SC injection each week for 4 weeks (Weeks 0-3 during Intervention Period 1 or Weeks 8-11 during Intervention Period 2 for Population 1 or Weeks 0-3 during Intervention Period 1 for Population 2)

one IV infusion of 4.5 mg/kg over a period of not less than 2 hours at Week 0 in Intervention Period 1 or Week 8 in Intervention Period 2 for Population 1 or at Week 0 in Intervention Period 1 for Population 2

one SC injection each week for 4 weeks (Weeks 0-3 in Intervention Period 1 or Weeks 8-11 in Intervention Period 2 for Population 1 or at Weeks 0-3 in Intervention Period 1 for Population 2)

one IV infusion over a period of not less than 2 hours at Week 0 in Intervention Period 1 for Population 1 and Population 2 or at Week 8 in Intervention Period 2 for Population 1