- Participants at screening (Visit 1) and baseline (Visit 2) with a Mayo assessment score of greater than or equal to 4 (≥ 4) but less than or equal to 10 (≤ 10) and with an endoscopy score of at least 1 (≥ 1) , following an adequate exposure to oral and/ or topical 5-ASA, in the opinion of the investigator;