Acute severe ulcerative colitis (ASUC) is a serious presentation of ulcerative colitis (UC) that carries a high risk for medical failure. First line therapy relies on IV corticosteroids, however up to 30% of patients will not respond. Even when second line rescue therapy with infliximab or cyclosporine is used, there is still significant rates of medical failure leading to an unplanned and irreversible surgery. In recent years, increasing numbers of patients admitted with ASUC have already failed infliximab therapy, highlighting the need for additional treatment options for these patients.