Effectiveness of Vedolizumab in CD Patients Naïve to Anti-TNF

Effectiveness of Vedolizumab Therapy in Inducing Clinical Remission in CD Patients Naïve to Anti-TNF and Its Capability to Halt Disease Progression

Anti-cytokine antibodies, such as Infliximab (an anti TNF alfa chimeric antibody) and Adalimumab (an anti TNF alfa humanize antibody), have been developed and used in clinical practice for the treatment of patients with Crohn disease (CD). Unfortunately, their efficacy is limited. Based on these concepts, a new drug has been developed for IBD treatment. Vedolizumab (VDZ) is able to recognize the α4β7 heterodimer, and selectively blocks gut lymphocyte trafficking. The hypothesis of this study is that VDZ therapy may be to halt CD disease progression during time and modifying its natural history, using Lemann Index.

All patients who will enter in the study will be follow-up at weeks 2-6-14-22-30-38-46 or before in case of relapse. A relapse will be defined by an Harvey Bradshaw Index ≥ 5 for 2 consecutive weeks. The following data are to be recorded: Physical examination Adverse Event Review Weight in Kg Full blood count Biochemical series including serum iron, serum ferritin, C reactive protein (PCR), ESR (eritrosedimatation rate) Fecal Calprotectin VDZ fecal loos VDZ trough levels and antidrug antibodies Current treatments The last visit will be performed at week 54. The following data are to be recorded: Physical examination Adverse Event Review Weight in Kg Full blood count Biochemical series including serum iron, serum ferritin, C reactive protein (PCR), ESR (eritrosedimatation rate) Fecal Calprotectin VDZ fecal loos VDZ trough levels and antidrug antibodies Current treatments Routine lower and upper gastrointestinal endoscopy and magnetic resonance imaging or computed tomography of the small bowel SES-CD Lemann Index

Primary responders will defined as by a decrease of Harvey Bradshaw Index at week 14 of 3 point from the Harvey Bradshaw Index calculate at week 0.

The investigators will evaluated the VDZ quantity (microgram) that a patients with mucosal ulcers could loss in patients feces.

Inclusion Criteria: Have given written informed consent to participate Be aged between 18 and 80 Have a moderate/severe CD defined by an HBI >7 CD Exclusion Criteria: previous treatment with anti-TNF drugs, concomitant use of immune-modulator drugs for CD (azathioprine/6-mercaptopurine, methotrexate) ulcerative colitis (UC) or inflammatory bowel disease undetermined (IBD-U) diagnosis symptomatic obstructive disease bowel resection within the past 6 months ileostomy extensive small bowel resection (as determined by the investigator) or a short bowel syndrome patients who are currently receiving total parenteral nutrition history of cancer in the past 5 years pregnancy known at the study inclusion positive Clostridium difficile stool assay Listeria, human immunodeficiency virus, central nervous system demyelinating disease, untreated tuberculosis