Study of Advanced Therapies for the Treatment of Adult Participants With Moderately to Severely Active Crohn's Disease or Ulcerative Colitis

Crohn's disease (CD) and Ulcerative colitis (UC) are 2 types of inflammatory bowel diseases which cause long-lasting, severe inflammation (redness, swelling) in the digestive tract. CD can affect any part of the digestive tract causing many different symptoms including belly pain, diarrhea, tiredness, and weight loss. UC affects the lining of the rectum and colon (large intestine) and can cause bleeding, belly pain, and diarrhea. This platform basket study will evaluate how safe and effective advanced therapies are in adults with moderately to severely active Crohn's Disease (CD) or Ulcerative Colitis (UC). This study currently includes 2 substudies evaluating different treatments in participants with CD or UC. Substudy 1 will evaluate the combination of risankizumab and trosunilimab (ABBV-466) and Substudy 2 will evaluate the combination of risankizumab and ABBV-701 (ABBV-7066). When adult participants with moderately to severely active CD or UC join the study, they will undergo a 2-step randomization within CD and UC substudies, respectively. The first unblinded randomization will assign participants into a substudy, and the second blinded randomization will assign participants to a treatment arm within the assigned substudy. Approximately 100 adult participants will be enrolled per treatment arm across both substudies at approximately 400 sites worldwide. There may be higher treatment burden for participants in this trial compared to their standard of care treatment without participating in this study. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, stool tests, endoscopies, checking for side effects and completing questionnaires and a daily diary.