Ulcerative colitis (UC) is a chronic disease of unknown etiology characterized by infiltration of inflammatory cells into the intestinal tract. OKT3 is an approved drug for intravenous use in the treatment of solid-organ transplantation. However, intravenous dosing has been limited by significant toxicities. Data from animal models suggest that antibody recognizing the T3 antigen complex Cluster of Differentiation 3 (anti-CD3) administered via the oral route is effective at treating a variety of autoimmune diseases. No side effects were observed in a recent phase I study of healthy participants receiving oral anti-CD3 monoclonal antibody (mAb).~The objectives of the current study are to assess the safety, immunologic effects and efficacy of short-term oral administration of OKT3 in participants with active ulcerative colitis. OKT3 will be delivered orally as a 1 milligram (mg) or 2 mg dose with Omeprazole 20 mg daily for 30 consecutive days in an open-label pilot trial. Thirty two participants will be screened for a targeted completion of 16 enrolled participants. The participants will be evaluated at baseline, day 1, day 2, week 1, week 3, as well as after completion of therapy at week 5 and 10 after the initiation of treatment. Lab tests will be performed at screening, baseline, day 2, week 1, week 3, week 5 and week 10. Clinical data will be collected at all study visits and via diary entries throughout the study period. A flexible sigmoidoscopy will be done at baseline and at week 5. Stool studies will be performed at screening to rule out infection.~To be eligible for this study, participants must be between the ages of 18 and 65 years and have a history of moderately to severely active UC as defined by a Mayo score of 6 to 12. They may not be taking concurrent biologic or immunomodulator therapy for UC.
This study will assess the safety and efficacy of orally delivered short-term OKT3 in participants with active ulcerative colitis.