A Study of Safety and Effectiveness of Ustekinumab in Patients With Moderate to Severe Active Crohn's Disease Who Have Been Previously Treated With Anti-TNF Therapy

In Crohn's disease there is inflammation (changes in body tissue which normally happen during
injury or infection) and or ulceration (open sores) in the intestines.This occurs because the
immune system (the part of the body that fights off infection) has an abnormal and overactive
response against the intestine and bowel tissues of the body. Crohn's disease is usually
treated with medications that either directly decrease inflammation or decrease the general
activity of the immune system to improve the diarrhea, abdominal pain, and other symptoms of
Crohn's Disease. Ustekinumab antibodies (natural substances made by your immune system to
stick to and help remove foreign materials in your body that cause diseases) have been
created to stick to and block the activity of two of the immune substances thought to cause
abnormal inflammation of Crohn's disease. Patients who are eligible and who have received
Remicade, Humira, or Cimzia and failed or been intolerant to one of these drugs will be
randomized to either active drug (ustekinumab) or placebo. All patients will be randomized
(like flipping a coin) at week 0 to be in one of 4 groups. At week 0 the study drug will be
given by IV administration and at weeks 8 and 16 by subcutaneous injection. There will be 11
study visits in total and the study will continue until week 36. Blood and stool samples will
be collected and studied, questionnaires to check on how you are doing in terms of your
disease will be completed, an Electrocardiogram (EKG) obtained, safety evaluations conducted
and diary cards distributed to be completed during the entire study. One of 4 groups: Grp
1-placebo, Grp 2-active drug 1mg/kg IV, Grp 3-active drug 3mg/kg IV, Grp 4-active drug 6mg/kg
IV. Based on the clinical response status at Week 6, patients from Grps 2, 3 and 4 will be
re-randomized at week 8 to receive either placebo or 90 mg SC at both weeks 8 and 16 and
patients from Grp 1 will receive placebo at Week 8 and Week 16 or a 270 mg SC injection at
Week 8 and 90 mg SC at Week 16.

Inclusion Criteria:

- Must have Crohn's disease or fistulizing Crohn's disease of at least 3 months duration

- Must have received Remicade, adalimumab or Cimzia at a dose approved for the treatment
of Crohn's disease

- Must have failed or been intolerant to Remicade, Humira or Cimzia for treatment of
Crohn's disease

- Must be 18 years of age or older

- Must have active Crohn's disease according to the Crohn's Disease Activity Index (CDAI
> =220 and < =450).

Exclusion Criteria:

- Patients who have had any kind of bowel resection, diversions or placement of a stoma
within 6 months

- Are pregnant, nursing or planning pregnancy (both men and women) while enrolled in the
study or within 1 year after receiving study agent

- Patients who have received Remicade, Humira or Cimzia < =8 weeks before the first
administration of study drug

- Patients with certain complications of Crohn's disease that would make it hard to
assess response to study drug

- Patients with a history of or ongoing chronic or recurrent infectious disease.