∙ Participants are eligible to be included in the study only if all of the following criteria apply:

• Male or female participants aged 18 to 75 years inclusive, at the time of signing the informed consent

• Participants who have had clinical evidence of active UC for ≥3 months before screening and confirmed by endoscopy during the screening period

• Must have active moderate-to-severe UC at screening as defined by a modified Mayo Score (mMS) of 5 to 9 (without the Physician Global Assessment (PGA), with a minimum Rectal Bleeding (RB) subscore ≥1, a minimum Stool Frequency (SF) subscore ≥1, mMES ≥2 confirmed by central reader, a minimum sum of all subscores of 5, and a minimum disease extent of 15 cm from the anal verge

• Must have received prior treatment for UC (either a or b below or combination of both):

‣ History of inadequate response to, loss of response to or intolerance to standard treatment with any of the following compounds: amino-salicylates, corticosteroids, methotrexate, azathioprine, or 6-mercaptopurine, or history of corticosteroid dependence (defined as an inability to successfully taper corticosteroids without recurrence of UC) AND history of no prior exposure to Advanced Therapies (ATs), such as a biologic agent used to treat UC or advanced small molecules used to treat UC

⁃ History of inadequate response to, loss of response to or intolerance to treatment with ≥1 approved AT such as a biologic agent used to treat UC or advanced small molecules used to treat UC

• Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies