Mesenchymal stromal cell therapy for the treatment of proctitis in ulcerative colitis

a) Men and women ≥ 18 years of age;

b) Patient must have UC confirmed by endoscopic and histologic evidence;

c) Inflammation must be limited to the rectum (up to 15 cm beyond the anal verge), confirmed by endoscopy maximum 3 months before baseline (slight inflammation in other parts of the colon is accepted with a maximum Mayo Score of 1);

d) Moderate to severe proctitis indicated by a Mayo Score of 2 or 3;

e) Proctitis must be refractory to conventional medical therapy. Which means that at some time during the course of the disease, patient must have received rectal 5-ASA therapy and rectal corticosteroid therapy for at least 4 weeks which did not result in an adequate response to treatment;

f) If treated with rectal therapy, therapy must be stopped two weeks before endoscopic implantation of MSCs and only restarted after 6 weeks;

g) If treated with oral 5-ASA therapy, dose must be stable for 4 weeks prior to study entry and remain on same dose during the first 6 weeks after MSC treatment;

h) If treated with oral corticosteroids, dose must be stable for 2 weeks prior to study entry and remain on same dose during the first 6 weeks after MSC treatment;

i) If treated with 6-mercaptopurine, methotrexate, azathioprine, vedolizumab or anti-TNF therapy patients must have been on medication for 3 months and a stable dose for 2 months prior to study entry and remain on same dose during the first 6 weeks after MSC treatment;

j) If female and of child-bearing age, patient must be non-pregnant, non-breastfeeding, and use adequate contraception;

k) Patient is willing to participate in the study and has signed the informed consent.

Consent must be obtained prior to any study procedure.

a) Patients suffering from renal- or hepatic failure;

b) Use of any investigational drug within 1 month prior to screening or within 5 half-lives of the investigational agent, whichever is longer;

c) Positive stool culture for enteric pathogens (salmonella, shigella, and campylobacter), positive C. difficile toxin, or positive stool ova and parasite exam;

d) All active infections requiring treatment;

e) Patients who had tuberculosis or an opportunistic infection (e.g., herpes zoster [shingles], cytomegalovirus, Pneumocystis carinii, aspergillosis, histoplasmosis) within 6 months prior to screening;

f) Malignancy within the past 5 years (except for squamous or basal cell carcinoma of the skin that has been treated with no evidence of recurrence);

g) Any dysplasia in the colon in the past 5 years;

h) Very severe proctitis; expected to result in hospitalization/ surgery within 3 months;

i) Previous treatment with allogeneic MSCs;

j) Any other condition which in the opinion of the investigator would make the patient unsuitable for enrollment, or could interfere with the patient participating in and completing the study;

k) Patient is unwilling or unable to comply with the study procedures.