 In Study NCT00055497, all participants received 40 mg of adalimumab subcutaneously SC at Baseline Week 0 and Week 2 of Study NCT00055497. Baseline of Study NCT00055497 is synonymous with NCT00055523 Week 4. At Week 4 of Study NCT00055497, participants were randomized based on their clinical remission status at Baseline and Week 4 of Study NCT00055497. Participants who demonstrated clinical remission defined as a Crohns Disease Activity Index CDAI score 150 points at Baseline of Study NCT00055497 and who remained in clinical remission at Week 4 of Study NCT00055497 those participants constituted the randomized analysis set were randomized to receive 1 of 3 blinded treatments: adalimumab 40 mg every other week eow, adalimumab 40 mg every week ew, or placebo. Participants who did not demonstrate clinical remission at Baseline of Study NCT00055497, or who were no longer in clinical remission at Week 4 of Study NCT00055497 were assigned to receive OL adalimumab 40 mg eow; those participants constituted the OL analysis set. At any time during Study NCT00055497, participants receiving OL adalimumab 40 mg SC eow who developed a flare or were non-responders during OL treatment could have had hisher dose increased to 40 mg SC weekly. Participants who were documented as having completed Week 56 are counted in the study completion total. 