Study to Test the Effect of CDP870 in the Treatment of Crohn's Disease Over 26 Weeks, Comparing CDP870 to a Dummy Drug (Placebo), Following 3 Doses of Active Drug (CDP870).

A Phase III Multi-national, Multi-centre, Double-blind Placebo-controlled Parallel Group, 26 Week Study to Assess the Maintenance of Clinical Response to Humanised Anti-TNF PEG Conjugate, CDP870 400 mg sc, (Dosed 4-weekly From Weeks 8 to 24), in the Treatment of Patients With Active Crohn's Disease Who Have Responded to Open Induction Therapy (Dosed at Weeks 0, 2 and 4) With CDP870

A 26 week maintenance study of CDP870 in Crohn's disease

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.
• Patients aged 18 years or above at screening.

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.