Abrilumab (AMG 181) in Adults With Moderate to Severe Crohn's Disease

Inclusion Criteria:

• Diagnosed with ileal, ileo-colonic, or colonic Crohn's disease for a minimum of 6months prior to baseline

• Moderately to severely active Crohn's disease defined by a CDAI score ≥ 220 and ≤ 450at baseline

• Evidence of active inflammation within 12 weeks prior to baseline

• Demonstrated an inadequate response to, loss of response to, or intolerance to atleast one of the following agents: Immunomodulators and/or anti-tumor necrosis factor (TNF) agents or to corticosteroids (non-US sites only).

• Neurological exam free of clinically significant, unexplained signs or symptoms duringscreening and no clinically significant change prior to randomization

• Subject has no known history of active tuberculosis and has a negative test fortuberculosis during screening

Exclusion Criteria:

• Short bowel syndrome

• Stricture with obstructive symptoms within 3 months

• Bowel surgery within 12 weeks prior baseline, or has planned bowel surgery within 24weeks from baseline

• Ileostomy and/or colostomy

• Any gastric or intestinal pouch

• Evidence of an infected abscess

• Bowel perforation or evidence of non-inflammatory obstruction during the 6 monthsprior to baseline

• Stool positive for C. difficile toxin at screening

• Any uncontrolled or clinically significant systemic disease

• Known to have tested positive for hepatitis B virus surface antigen, hepatitis C virusantibody, or human immunodeficiency virus (HIV)

• Any underlying condition that predisposes subject to infections

• Subject has malignancy (other than resected cutaneous basal or cutaneous squamous cellcarcinoma, or treated in situ cervical cancer considered cured) within 5 years ofbaseline

• Received an anti-TNF agent, cyclosporine, mycophenolate mofetil, sirolimus (rapamycin), thalidomide, tacrolimus, topical (rectal) aminosalicylic acid (eg,mesalamine) or topical (rectal) steroids, intravenous or intramuscular corticosteroidswithin protocol-specified time periods.

• Any prior exposure to antagonists of integrins or integrin ligands (eg, natalizumab,efalizumab, or vedolizumab), rituximab, or TNF kinoid immunotherapies, AMG 181, or anyform of cell-based transplantation

• Received treatment of infection with intravenous (within 30 days of baseline) or oral (within 14 days prior to baseline) antibiotics, antivirals, or antifungals

• Significant laboratory abnormalities

• Pregnant or breast feeding