Is Local Injection of Mesenchymal Stem Cells After Endoscopic Dilation Safe and Does it Improve the Outcome of Intestinal Stricture in Patients With Crohn's Disease?

This is an exploratory phase II study, to evaluate the impact of these Mesenchymal Stem Cells (MSCs) on strictures in Crohn's disease patients with symptomatic intestinal stricture eligible to endoscopic dilatation. The impact of combined treatment by endoscopic dilation and local injection of MSCs will be compared with that of a control group.


Eligibility Criteria:
Inclusion Criteria:

* Patient aged ≥ 18 years with Crohn's Disease diagnosed more than 6 months ago
* Background treatment, for Crohn's Disease, stable for 4 months
* Presence of stricture (whether de novo or anastomotic), meeting the radiological definition of stenosis, i.e. a combination of the following criteria: (1) localized luminal narrowing (reduction of luminal diameter by at least less than 50% compared to adjacent healthy bowel segment), (2) bowel wall thickening (25% increase in wall thickness compared to adjacent unaffected bowel) and pre-stenotic dilation (luminal diameter greater than 3 cm)
* Presence of symptomatic stricture with abdominal pain after meals and limitations on the amount or type of food at screening
* Presence of a stenosis accessible by ileo-colonoscopy, not passable (i.e. not allowing the passage of the adult ileo-colonoscope), of a length less than 5 cm, eligible for endoscopic dilation
* Patient accepting the study protocol and having signed an informed consent
* Patient capable of undergoing entero-MRI

Exclusion Criteria:

* Patient liable for immediate surgery
* Patient with intra-abdominal fistula or abscess
* Patient with a stenosis not accessible to ileocolonoscopy
* Patient presenting ≥ 2 strictures with impossibility of determining which stenosis is "dominant" and responsible for the symptoms (based on dilation in entero-MRI)
* Patient with a stenosis longer than 5 cm
* Patient with a contraindication to performing an entero-MRI or to the use of contrast product injection in entero-MRI (Gadolinium)
* Pregnant woman or planning a pregnancy in the year
* Patient with kidney insufficiency (with anuria, glomerular filtration rate \< 30 ml/min or on dialysis), hepatic insufficiency (presence of fulminant hepatitis, cirrhosis with signs of portal hypertension, acute alcoholic hepatitis, esophageal varices, history of gastrointestinal bleeding following rupture of esophageal varices, hepatic encephalopathy, prolonged prothrombin time, ascites secondary to portal hypertension, bacterial or fungal liver abscess, biliary obstruction, chronic viral hepatitis with a total serum bilirubin level \> 3 mg/dL)
* Patient with documented human immunodeficiency virus (HIV) infection, active hepatitis B or C or tuberculosis
* Patient having presented an opportunistic infection in the 6 months preceding inclusion or a serious infection in the previous 3 months
* Patient who has developed a malignant tumor with a history of lymphoproliferative disease with the exception of: non-melanoma skin cancer, carcinoma in situ (e.g. skin, cervix, bladder, breast) and in remission for at least 3 years prior to screening, superficial bladder cancer, asymptomatic low-grade or localized curatively treated prostate cancer for which the "watch-and-wait" approach is the standard of care as well as any other cancer that has been in remission for ≥ 3 years prior to enrollment.