Purpose of the study is to test whether adalimumab can induce clinical remission in subjects with active Crohn's disease when compared to placebo (an inactive substance)

Inclusion:

• Diagnosis of Crohn's disease
• CDAI score at baseline of between 220 and 450
• Normal laboratory parameters
• Willing and able to give informed consent

Exclusion:

• Diagnosis of ulcerative colitis
• Women cannot be pregnant or breastfeeding
• No previous use of infliximab or other anti-TNF antagonists
• No previous history of tuberculosis or listeria infection
• No previous history of cancer other than successfully treated skin cancer