GSK1605786A in the Maintenance of Remission in Subjects With Crohn's Disease

This is a multi-centre, randomised, placebo-controlled, double-blind parallel group study in
adult subjects with Crohn's disease who previously achieved clinical response (CDAI decrease
of at least 100 points) and/or remission (CDAI less than 150) in a prior Phase III induction
study (Study CCX114151 or another GSK sponsored induction study). Subjects will be
randomised to 52 weeks of oral treatment with GSK1605786A 500 mg once daily or 500 mg twice
daily or placebo. Subjects who are receiving concomitant corticosteroids at entry will
undergo dose tapering following a defined schedule. Subjects who complete the treatment
period may be eligible to enter an open-label extension study. Subjects who experience
disease worsening and require additional (rescue) treatment will be withdrawn and may be
eligible to enter the open-label study. Subjects who do not enter the open-label study must
complete a follow-up assessment 4 weeks after completion of treatment. Approximately 756
subjects will be enrolled.

Inclusion Criteria:

- Subjects achieving clinical response (CDAI decrease of at least 100 points) and/or
remission (CDAI less than 150) upon completion of treatment in Study CCX114151 or
another GSK sponsored induction study

- Written informed consent prior to any CCX114157 specific study procedures

- Females of child-bearing potential must be sexually inactive or commit to use of
consistent and correct use of contraceptive methods with a failure rate of less than
1 percent

- Stable doses of Crohn's disease medications

- Subjects on corticosteroids at entry must be willing to undergo corticosteroid dose
taper during the study

Exclusion Criteria:

- If female, is pregnant, has a positive pregnancy test or is breast-feeding

- Subjects with known or suspected coeliac disease or a positive screening test
(anti-tissue transglutaminase antibodies) should have been excluded from enrolment
into the induction studies. Subjects in whom a diagnosis of coeliac disease is
subsequently suspected should have this excluded with testing for anti-tissue
transglutaminase antibodies prior to enrolment into the maintenance study.

- Known or suspected fixed symptomatic small bowel stricture

- Enterocutaneous, abdominal or pelvic fistulae likely to require surgery during the
study period

- Current sepsis or infections requiring intravenous antibiotic therapy for greater
than 2 weeks

- Evidence of hepatic dysfunction, viral hepatitis, or liver function abnormalities