Observational Study Evaluating the Effectiveness of Drug Concentration to Predict the Recapture of Response in Crohn's Disease Patients With Loss of Response ( PRADA )

Inclusion criteria

• Documented diagnosis of Crohn's Disease.
• Treatment with adalimumab, for a minimum of 16 weeks, as per clinical practice, at a dose of 160 mg at week 0, 80 mg at week 2, and then 40 mg q2w with a documented response as defined by the investigator.
• Current evidence of active inflammatory disease/LOR defined as the presence of active inflammation (confirmed with a CRP ≥ 5 mg/L and/or a fecal calprotectin ≥ 250µg/g.
• Ability of subject to participate fully in all aspects of this clinical trial.
• Written informed consent must be obtained and documented.

Exclusion criteria

• Primary non-responders to 16 weeks of adalimumab therapy.
• Received any investigational drug within the 16 weeks of adalimumab therapy.
• Serious underlying disease other than CD that, in the opinion of the investigator, may interfere with the subject's ability to participate fully in the study.
• History of alcohol or drug abuse that, in the opinion of the investigator, may interfere with the subject's ability to comply with the study procedures.
• Stools positive for Clostridium difficile.
• Pregnant or lactating women.
• Current enrolment in any other interventional research study.
• Presence of perianal or abdominal abscess.