This study will look at how safe and tolerable different treatments are for adults who have moderate to severe ulcerative colitis (UC). The platform design uses one single master protocol that explains how the overall study is organized, whereas each treatment, as sub-study will be tested to see how well the study drug works and how it affects participants.
Diagnosis of UC for greater than or equal (>=) 3 months before screening. Appropriate documentation of endoscopy and biopsy results consistent with the diagnosis of UC, in the assessment of the investigator, must be available.
Active UC with a modified Mayo score (mMS) of 5 to 9 points and endoscopy sub score of 2 to 3 within 14 days before baseline biopsy collection.
Active disease beyond the rectum (greater than [>]15 centimeter [cm] of active disease from the anal verge at the screening colonoscopy).
Documentation of a surveillance colonoscopy (performed according to local standard) within 12 months before screening (may be performed during screening) for participants with pancolitis of >8 years duration or left-sided colitis of >12 years duration, or primary sclerosing cholangitis
Participants with current diagnosis of Crohn's disease (CD) or Inflammatory bowel disease-unclassified (IBD-U) or a history of radiation colitis, microscopic colitis or ischemic colitis.
Have currently known complications of UC such as fulminant colitis, or toxic megacolon, stoma, or stricture/stenosis within the small bowel or colon.
Have prior history of dysplasia of the gastrointestinal tract or found to have dysplasia, other than completely removed low-grade dysplastic lesions, in any biopsy performed during the screening endoscopy.
Have a history of malignant neoplasm within the last 5 years.