Mirikizumab Administered at the Same Time as Tirzepatide in Adult Participants With Moderately to Severely Active Ulcerative Colitis and Obesity or Overweight: Phase 3b Study

Inclusion Criteria: * Have had an established diagnosis of UC for ≥3 months before baseline which includes endoscopic evidence of UC and a histopathology report that supports a diagnosis of UC. * Have moderately to severely active UC as defined by a modified Mayo score (mMS) of 5 to 9 points and endoscopic subscore (ES) of 2 to 3 (confirmed by central review) within 21 days before baseline. * Participants with a history of UC for greater than or equal to 8 years who have had a surveillance colonoscopy completed within 1 year prior to baseline must have documented negative results for colorectal dysplasia and cancer. * Have obesity, \[body mass index (BMI) 30 kilograms per meter squared (kg/m2)\] * Have overweight (BMI ≥27 kg/m2 to \<30 kg/m2) and in the presence of at least 1 of these weight-related comorbid conditions: * hypertension * Type 2 Diabetes Mellitus (T2DM) * dyslipidemia * obstructive sleep apnea, or * cardiovascular disease. * Have an inadequate response to, loss of response to, or intolerance to at least 1 of the conventional medication: oral corticosteroids, oral azathioprine (AZA) or 6-mercaptopurine (6-MP), or oral 5-aminosalicylates (for example, mesalamine, sulfasalazine, olsalazine, and balsalazide) and/or who have an inadequate response to or a loss of response to, or are intolerant to advanced therapy for UC, defined as: a biologic or biosimilar medication such as anti-tumor necrosis factor (TNF) antibodies; anti-integrin antibodies, Janus kinase (JAK) inhibitors such as tofacitinib or upadacitinib, sphingosine 1-phosphate receptor 1inhibitors such as etrasimod or ozanimod, or anti-interleukin(IL)-12p40 antibodies, for example, ustekinumab. Exclusion Criteria: * Have a current diagnosis of: * Crohn's disease * inflammatory bowel disease (IBD) unclassified (formerly known as indeterminate colitis), or * primary sclerosing cholangitis. * Have had or will need bowel resection or intestinal or intra-abdominal surgery. * Have evidence of toxic megacolon, or stricture or stenosis within the colon that cannot be traversed by a sigmoidoscope or colonoscope. * Have a diagnosis of Type 1 Diabetes Mellitus (T1DM) or have insulin-treated T2DM. * Have a history of severe hypoglycemia and/or hypoglycemia unawareness within the 6 months prior to screening. * Have a self-reported change in body weight greater than 5% (gain or reduction) within 3 months prior to screening. * Have a current or recent acute, active infection.