A 26 week study to examine the efficacy, safety and pharmacokinetics of CDP870 in Crohn's disease

Receiving immunosuppressants (azathioprine/6-MP/methotrexate) at Week 0 or not.

604 patients will be enrolled with 1006 patients screened (to allow for 25% screen failures between screening and Week 0 and expected presentation at Screening of 60% of patients with CRP < 10 mg/L and 40% of patients with CRP ≥ 10 mg/L).

Inclusion Criteria:

• Definitive diagnosis of Crohn's disease confirmed (at least 3 months prior to study entry) either by radiological, endoscopic or histological evidence, affecting the terminal ileum (L1), colon (L2) or ileocolon (L3*. *Vienna Classification (1998)
• Active Crohn's disease (≥ 220 and ≤ 450) scored over the 7 days prior to the first dose of study drug.
• Male and female aged 18 years or above at screening.
• Patients who meet all concomitant medication criteria in the protocol specified table. For all drugs being taken at screening, the patient should be able to remain on a stable dose throughout the duration of the study, although steroids may be tapered starting at Weeks 8 to 12.

Exclusion Criteria:

• Crohn's Disease Related
• Fistula abscess present at screening.
• Stricturing type disease with symptoms or signs of non-inflammatory mechanical obstruction or bowel perforation in last 3 months.
• Short bowel syndrome.
• Functional colostomy or ileostomy (note: patients who have had a temporary stoma in the past, which has been reversed, are eligible to enter the study).
• Positive stool laboratory results for enteric pathogens.