Hemorrhagic Proctocolitis Clinical Trials

⁃ Subjects who meet all of the following criteria can be included in this study:

• Subjects voluntarily take part in the study after being fully informed, sign a written informed consent form (ICF), and agree to follow procedures specified in the study protocol;

• Males and females, 18 to 70 years of age, inclusive at the time of signing of ICF;

• Have had an established diagnosis of ulcerative colitis (UC) of ≥ 3 months in duration prior to signing of ICF, which is supported by endoscopy reports, histopathology reports and clinical manifestations consistent with UC, as determined by investigators;

• Involved intestinal segment extending ≥ 15 cm from the anal verge as confirmed by a screening endoscopy;

• Active moderate to severe UC, defined by a modified Mayo score of 5 to 9 points at screening, which includes a stool frequency (SF) subscore of ≥ 2, a rectal bleeding (RB) subscore ≥ 1 and an endoscopic (ES) subscore of ≥ 2 (based on a screening endoscopy, confirmed by central reading);

• Documentation of an inadequate response, loss of response, or intolerance (defined as interruption of drug due to an adverse reaction as evaluated by the investigator) to a treatment course of 1 or more of the following standard of care medications:

• If a subject is using oral 5-ASAs, and/or oral glucocorticoids (≤ 20 mg/day of prednisone or equivalent dose, or ≤ 9 mg/day of budesonide or equivalent dose), and/or probiotics to treat UC, the dosage must remain stable for ≥ 2 weeks prior to the screening endoscopy and during the study period;

• If 5-ASAs and glucocorticoids have already been discontinued, they must have been discontinued for ≥ 2 weeks prior to the screening endoscopy;