Inclusion Criteria:

• Have Crohn's disease of at least 3 months' duration with colitis, ileitis, or ileocolitis, confirmed at some time in the past by radiography, histology, or endoscopy
• Have active Crohn's disease, defined as a baseline Crohn Disease Activity Index (CDAI) score of ≥ 220 and ≤ 450, with confirmation of active inflammation
• Has failed conventional therapy as demonstrated by having received corticosteroids and/or immunomodulators(ie, AZA, MTX, or 6-MP) at adequate therapeutic doses OR Have a history of failure to respond to or tolerate an adequate course of corticosteroids and/or immunomodulators (ie, AZA, MTX, or 6-MP) at adequate therapeutic doses OR Is corticosteroid dependent or has had a history of corticosteroid dependency AND Has not previously demonstrated failure of or intolerance to 1 or more TNF-antagonist therapies (ie, infliximab, adalimumab, or certolizumab pegol) per study criteria
• Have screening laboratory test results within protocol-specified parameters

Exclusion Criteria:

• Patients who have had any kind of bowel resection within 6 months
• Are pregnant or planning pregnancy (both men and women) while enrolled in the study or for 20 weeks after receiving study agent
• Patients who have received infliximab, adalimumab or certolizumab pegol ≤ 8 weeks before the first administration of study drug
• Patients with certain complications of Crohn's disease that would make it hard to assess response to study drug
• Patients with a history of or ongoing chronic or recurrent infectious disease
• Patients who have previously received a biologic agent targeting IL-12 or IL-23, including but not limited to ustekinumab (CNTO 1275) or briakinumab (ABT-874)