A follow-on Safety Study of CDP870 in Subjects With Crohn's Disease (CD) Who Have Completed a 26-week Double Blind Study CDP870-031 [NCT00152490] or CDP870-032 [NCT00152425]

Inclusion Criteria:

- Participation in either of the CDP870-031 [NCT00152490] or CDP870-032 [NCT00152425]
clinical studies in which the subject completed the trial at Week 26. Subjects may
have received active or placebo or both treatments in the prior study

- Subjects must be able to understand the information provided to them and give written
informed consent

Exclusion Criteria:

- Any exclusion criterion that would have prevented the subject's participation in the
qualifying pivotal study CDP870-031 [NCT00152490] or CDP870-032 [NCT00152425],
although the criterion that excludes previous participation in a clinical trial of
Certolizumab Pegol does not apply. In addition there are no limits on the Clinical
Disease Activity Index (CDAI) score at entry