Please select the eligibility criteria that correspond to the clinical trial below.
Title: Discontinuation of Infliximab Therapy in Patients With Crohn's Disease During Sustained Complete Remission: A Multi-center, Double Blinded, Randomized, Placebo Controlled Study
Brief Summary: The purpose of this study is to determine whether infliximab can favourably and safely be discontinued in patients with Crohn's disease in sustained complete clinical, biochemical, and endoscopic remission on infliximab.

Further to examine the clinical utility of measuring levels/activity of infliximab and activity of anti-infliximab Ab in patients in sustained complete remission, in order to investigate whether pharmacoimmunological data can predict the clinical outcome and rationalize therapeutic management of these patients with respect to continuation or discontinuation of infliximab therapy. Additional, to investigate the optimal time-point, out of three, to measure this activity.


Options:
A: Inclusion Criteria:

* Diagnosis of Crohn's disease.
* Male or female, age \> 18 years.
* Currently treated with a combination therapy with infliximab and anti-metabolites for luminal Crohn's disease.
* Combined therapy with scheduled infliximab and anti-metabolites for at least 8 months.
* Scheduled administration of infliximab 5 mg/Kg every 8 weeks over the last 4 months.
* Antimetabolites administered at a stable dosage for the last 3 months: at least 1 mg/Kg or 2 mg/Kg for mercaptopurine and azathioprine, respectively, or the highest tolerated dosage if intolerance to standard dose; at least 15 mg/week subcutaneously for methotrexate.
* Patients in steroid free clinical remission for at least 6 months according to retrospective assessment of the patients' files.
* CDAI \< 150 at baseline.
* A contraceptive during the whole study for childbearing potential female patients.
* Patients able to understand the information provided to them and to give written informed consent for the study

Exclusion Criteria:

* Patients who have presented a severe acute or delayed reaction to infliximab.
* Perianal fistulae as the main indication for infliximab treatment
* Active perianal/abdominal fistulae at time of inclusion, defined by active drainage
* Patients with ostomy or ileoanal pouch
* Pregnancy or planned pregnancy during the study
* Inability to follow study procedures as judged by the investigator
* Non-compliant subjects.
* Participation in another therapeutic study
* Steroid use ≤6 months prior to screening
* Currently receiving steroids, immunosuppressive agents (other than purine, methotrexate), biologic treatment (other than infliximab) or thalidomide
B: Inclusion Criteria:

* Luminal Crohn's disease defined according to standardized diagnostic criteria.
* Age ≥ 18 years.
* IFX induction treatment week 0, 2, 6 followed by maintenance therapy.
* IFX treatment length minimum 12 months. Episodic therapy with IFX pause \> 12 weeks is not accepted within the last year. The treatment interval in the last three months has to be of 6-10 weeks.
* Complete remission defined as:

  * CDAI score \< 150 and
  * Biochemical remission, and
  * No other signs of disease activity as evaluated by endoscopic examination or by magnetic resonance imaging (MRI).
* Stable remission, judged by the treating physician, at two consecutive treatments visits corresponding 2 scheduled IFX infusions. Thus, the first visit is during IFX maintaining therapy (screening visit). The second visit is at time of inclusion corresponding time of next scheduled IFX infusion (i.e. after ≈ 8 weeks).
* No use of oral steroids within 3 months prior to inclusion.
* Concomitant therapy with other immune suppressants, except steroids, is allowed. The dosage and frequency must have been stable three months prior to inclusion and must remain stable throughout the study period.

Exclusion Criteria:

* Initial indication for IFX being predominantly fistulizing perianal disease.
* Any contraindications for continuing IFX treatment, including prior acute or delayed infusion reaction to a TNF- inhibiting agent, any active infection requiring parenteral or oral antibiotic treatment, known infection with tuberculosis, human immunodeficiency virus (HIV) or hepatitis virus.
* Any condition including physician finds incompatible with participation in the study or the patient being unwilling or unable to follow protocol requirements.
C: Inclusion Criteria:

* Documented diagnosis of Crohn's disease
* Able to speak and understand English, French or Flemish
* Access to a telephone or email/internet service
* Written informed consent must be obtained and documented

Exclusion Criteria:

* Any conditions (e.g., history of alcohol or substance abuse) which in the opinion of the investigator , may interfere with the patients ability to comply with study procedures
* Participating in other investigational studies
D: Inclusion Criteria:

1. Patient must be able to understand the information given to him/her and give written informed consent.
2. Definitive diagnosis of Crohn's disease (confirmed by recent radiological, endoscopic and/or histological evidence according to international criteria) .
3. Age minimum 18 years.
4. Previous good response to at least 3 doses (5mg/kg) of infliximab (as judged by the treating physician).
5. Loss of response to standard doses of infliximab (as judged by the treating physician).
6. Last infliximab infusion given at least 4 weeks before inclusion.
7. For patients with luminal disease, the CDAI should be above 220 points at inclusion.
8. For patients with fistulising disease only, at least one draining perianal fistula (confirmed by radiography, MR, ultrasound or physical examination) should be present.

Exclusion Criteria:

1. Any contraindication to continued infliximab treatment
2. Short bowel syndrome
3. Bowel resection within 12 weeks of inclusion.
4. Current or recent history of severe, progressive, and/or uncontrolled renal, hepatic, haematological, gastrointestinal, endocrine, pulmonary, cardiac, neurological, or cerebral disease.
5. Pregnancy
6. History of alcohol or drug abuse within the prior year
7. Patients who do not meet concomitant medication criteria.
8. Any other condition, which in the Investigator's judgment would make the patient unsuitable for inclusion in the study.

Answer: B