Evaluation of PROCHYMAL® Adult Human Stem Cells for Treatment-resistant Moderate-to-severe Crohn's Disease

Inclusion Criteria: * failed (within last 2 yr) or intolerant of at least one steroid AND at least one immunosuppressant AND at EXACTLY one biologic * CDAI between 250 and 450, inclusive * endoscopically or radiographically confirmed Crohn's disease of ileus or colon or both * C-Reactive Protein Test (CRP) of at least 5 mg/l (0.5 mg/dl)\*OR\* CDAI of at least 300 * weight between 40 and 150 kg, inclusive * adequate renal function * negative tuberculosis skin (PPD) test (or evaluated low risk of TB activation) Exclusion Criteria: * HIV or hepatitis infection active * allergy to CT contrast agents, or to bovine or porcine products * symptomatic fibrostenotic Crohn's disease * permanent ostomy * biologic therapy within past 90 d * prednisone greater than 20 mg/d within past month * short-bowel syndrome * total parenteral nutrition * abnormal liver function * malignancy active within past 5 years (except completely resected basal or squamous cell carcinoma of skin) * enteric pathogens, including C. difficile * history of colonic mucosal dysplasia * current or prior evidence of tuberculosis (TB) (unless risk of activation or re-activation deemed low)