Inclusion Criteria:
* Participant must have successfully enrolled in and completed Study M06-806 through Week 52.
* Participant must have been a responder at any time point during the M06-806 study (defined as having achieved at least a 15-point reduction in the Pediatric Crohn's Disease Activity Index (PCDAI) from Baseline).
* If female, participants who were sexually active and of child-bearing potential were to be practicing an approved method of birth control throughout the study and for 150 days after study drug administration. Examples of approved methods of birth control included the following:
1. Condoms, sponge, foam, jellies, diaphragm or intrauterine device (IUD)
2. Oral, parenteral or intravaginal contraceptives
3. A vasectomized partner
* Participant of legal age, parent or legal guardian, as required, voluntarily signed and dated an Institutional Review Board (IRB)/Independent Ethics Committee (IEC) approved informed consent form, after the nature of the study was explained and the participant of legal age, participant's parent, or legal guardian, as required, had the opportunity to ask questions. Participants were to be included in all discussions, and if required, their signature on an assent form was to be obtained.
* Parent or legal guardian of participant who was not of legal age, as required, must have been willing to actively supervise storage and administration of study drug and to ensure that the time of each dose was accurately recorded in the participant's diary.
* Participants of legal age, must have been willing to actively store, administer, and accurately record study drug administration in the participant diary.
* Participant was judged to be in acceptable medical condition, as determined by the Principal Investigator based upon results of clinical and laboratory evaluations done throughout the preceding Crohn's disease study M06-806.
Exclusion Criteria:
* For any reason, the participant was considered by the Investigator to be an unsuitable candidate for continuing therapy in the M06-807 study.
* Participant had abnormal laboratory or other test results that in the opinion of the Investigator would make the participant unsuitable to participate in this study.
* History of cancer or lymphoproliferative disease other than a successfully and completely treated cutaneous squamous cell or basal cell carcinoma or carcinoma in-situ of the cervix.
* History of listeriosis, histoplasmosis, chronic or active hepatitis B infection, human immunodeficiency virus (HIV) infection, any immunodeficiency syndrome, central nervous system (CNS) demyelinating disease or active TB (receiving treatment or not receiving treatment). Ongoing severe infections such as sepsis and opportunistic infections were exclusionary.
* Participant with known, symptomatic obstructive strictures.
* Participant who was planning surgical bowel resection at any time point while enrolled in the study.
* Participant who had short bowel syndrome as determined by the Investigator.
* Participant who was receiving total parenteral nutrition (TPN).
* Participant who was unwilling to discontinue growth hormone prior to the first dose of open-label study drug at the Baseline visit of M06-807.
* Female participant who was pregnant or currently breastfeeding.
* Participant with a history of clinically significant drug or alcohol abuse in the last year.
* Participant with a poorly controlled medical condition such as: uncontrolled diabetes, recurrent infections, unstable ischemic heart disease, moderate to severe heart failure, recent cerebrovascular accidents or any other condition which, in the opinion of the Investigator or the Sponsor, would put the participant at risk by participation in the protocol.
* Participant with any prior exposure to Tysabri (natalizumab).
* Participant with a known hypersensitivity to the excipients of adalimumab as stated in the label.
* Participant with a previous history of dysplasia of the gastrointestinal tract.
