include but are not limited to the following: - Has had ulcerative colitis (UC) (from onset of symptoms) for at least 3 months before Randomization - Has moderately to severely active UC - Has a weight ≥40 kg - Satisfies at least 1 of the criteria: Has had an inadequate response or loss of response to 1 or more protocol-specified treatments; protocol specified corticosteroid dependence; has been intolerant to 1 or more protocol-specified UC treatments - Is on treatment with any protocol-specified drugs during the study and meets drug stabilization requirements, as applicable The main

include but are not limited to the following: - Has a diagnosis of Crohn's Disease (CD) or indeterminate colitis (inflammatory bowel disease (IBD)-undefined) or other types of colitis or enteritis that may confound efficacy assessment - Has a current diagnosis of fulminant colitis and/or toxic megacolon - Has UC limited to the rectum - Has a current or impending need for colostomy or ileostomy - Has had a total proctocolectomy or partial colectomy - Has UC exacerbation requiring hospitalization within 2 weeks before Screening - Has any active infection as specified in the protocol - Is known to be infected with hepatitis B virus (HBV), hepatitis C virus (HCV), or human immunodeficiency virus (HIV) - Has evidence of active tuberculosis (TB) or meets TB exclusionary parameters - Has a history of cancer (except fully treated nonmelanoma skin cell cancers or cervical carcinoma in situ after complete surgical removal) and is disease free for <5 years before Randomization or has a history of colorectal cancer at any time - Has prior or current evidence of definite colonic dysplasia except for low-grade dysplasia that has been completely removed - Has had major surgery within 3 months before Screening or has a major surgery (ie, surgical procedure requiring general anesthesia) planned during the study - Has received protocol-specified prohibited medications