Must have an established diagnosis of Ulcerative Colitis (UC) or Crohn's Disease (CD) for at least 3 month duration, which includes clinical and endoscopic evidence of UC or CD and a histopathology report that supports a diagnosis of UC or CD.
For UC:
* Have moderately to severely active UC as defined by a modified Mayo score (mMS) of 5-9 points and Endoscopic Subscore (ES) greater than or equal to (≥) 2, confirmed by the central reader and rectal bleeding (RB)≥1, with endoscopy performed within 21 days prior to Visit 2.
For CD:
* Have moderately to severely active CD as defined by a Crohn's disease activity index (CDAI) score ≥ 220 and less than or equal to (≤) 450. Have a centrally read Simple Endoscopic Score for Crohn's Disease (SES-CD) score ≥6 for participants with ileal-colonic or ≥4 for participants with isolated ileal disease within 21 days before the randomization
Must have demonstrated an inadequate response, loss of response, or intolerance to at least one of the following: corticosteroids, immunomodulators, or an advanced therapy for UC or CD
Have screening laboratory test results within the protocol specified parameters.
You may not be if
Must not have a current diagnosis of inflammatory bowel disease (IBD)-unclassified or primary sclerosing cholangitis
* For UC - must not have a current diagnosis of CD
* For CD - must not have a current diagnosis of UC
Must not have had or will need bowel resection or intestinal or intra-abdominal surgery as specified in the protocol
Must not have complications of UC or CD, including but not limited to stricture or stenosis (some exceptions allowed for CD) or short bowel syndrome
Must not have a significant uncontrolled illness that in the opinion of the investigator may compromise the participant's safety or interfere with interpretation of data
Must not have failed more than 5 approved advanced treatments for UC or CD with different mechanisms of action
Must not have failed an anti-interleukin-23p19 (anti-IL-23p19) antibody treatment
Must not have received or will need any prohibited medications for UC or CD as specified in the protocol
Clareo Health | A Master Protocol (IIBD): A Study of Multiple Drugs in Adults With Ulcerative Colitis or Crohn's Disease