Safety and Tolerability of FITC-Adalimumab Administration During Confocal Laser Endomicroscopy of the Gut

Inclusion Criteria: Trial subjects must meet all of the following inclusion criteria: * Male and female subjects from 18 to 70 years of age who are capable of giving informed consent without any restrictions * Endoscopically and histologically confirmed diagnosis of Crohn's disease (CD) * Manifestation of CD in the colon and/or in the terminal ileum * Currently active CD with a CDAI score \>150 * Clinically inadequate response of CD to systemic glucocorticoids and/or immunosuppressants (azathioprine, 6-mercaptopurine, methotrexate) or glucocorticoid-dependent CD or any contraindication to glucocorticoids * Indication for treatment with Adalimumab * Indication for intestinal confocal laser endomicroscopy prior to institution of adalimumab therapy * Subject is mentally capable of understanding the nature and purpose/conduct of the clinical trial and of following the study staff's instructions * Subject has given written informed consent after being informed by an investigator Female subjects additionally must meet at least one of the following criteria: * Must be menopausal (at least 12 months' natural amenorrhea or 6 months' amenorrhea with serum FSH \>40 mU/mL) or * Must have undergone bilateral oophorectomy or hysterectomy or * Must be a regular, correct, and reliable user of a contraceptive method with a failure rate of \<1% per year (such as oral contraceptives, implants, depot shots, intrauterine device, hormone coil) * Must have a vasectomized partner Exclusion Criteria: * Subjects must not meet any of the following exclusion criteria: * Impaired blood clotting (prothrombin rate \<50% and/or PTT \>55 sec and/or a platelet count of \<50,000/μL) * Pregnancy and lactation Contraindications to treatment with adalimumab: * Moderate to severe heart failure (NYHA Class III/IV) * Active tuberculosis * Severe acute infections, e.g. sepsis * Opportunistic infections including invasive fungal infections * Known hypersensitivity to any of the ingredients of the study product or to any drug with a similar chemical structure * Treatment with beta-receptor blocking agents (because of altered symptoms in case of possible anaphylactic reactions to IV fluorescein) * Any other condition or medical treatment that, in the investigator's judgment, is not compatible with participation in the trial * Individuals who are in a relationship of dependence on or employed by the sponsor or any of the investigators * Planned prolonged stay outside the region of the study site, preventing the subject from returning for scheduled visits * Participation in any other clinical trial or administration of any investigational drug within the last four weeks prior to the screening visit