A Study to Investigate the Efficacy and Safety of Dupilumab Therapy Compared With Placebo in Participants Aged ≥18 Years With Moderately to Severely Active Ulcerative Colitis With an Eosinophilic Phenotype (LIBERTY-UC SUCCEED (Study in UC for Clinical Efficacy Evaluation of Dupilumab))

Eligibility Criteria

• * Participants must be ≥18 years of age at the time of signing the informed consent.
• * Evidence of biomarker enrichment at time of screening.
• * Moderately to severely active UC, defined as a baseline modified Mayo score of 5 to 9, inclusive, using the Mayo endoscopic subscore assigned during the concurrent local and central reading of the video endoscopy.
• * Has a screening endoscopy with ≥2 endoscopic subscore in the Mayo score component assessment as determined by concurrent local and central reading of the video endoscopy.
• * Has a baseline rectal bleeding subscore of ≥1 and baseline a stool frequency score of ≥1 as determined by the Mayo score component assessment.
• * Participants with inadequate response/non-response, loss of response, or are intolerant of standard biologic therapy for their UC AND/OR Inadequate or non-responders, have shown loss of response, or are intolerant to at least 1 of the following treatments: oral corticosteroids (≤20 mg/day), 5-aminosalicylic acid (ASA) compounds, immunomodulators, small molecules.
• * Severe extensive colitis as evidenced by:
• * Current hospitalization
• * Likely to require surgery for the treatment of UC within 12 weeks of Screening Visit
• * UC limited to the rectum only or to \<20 cm of the colon as determined by central reading.
• * Presence of an ileal pouch, ostomy, stoma or fistula or history of a fistula.
• * Require, or required within the 2 months before screening, surgery for active gastrointestinal bleeding, peritonitis, intestinal obstruction, or intra-abdominal or pancreatic abscess requiring surgical drainage, or other conditions possibly confounding the evaluation of benefit from study agent treatment.
• * Has a prior medical history of eosinophilic colitis.
• * Participants with abdominal abscess, fulminant disease, or toxic megacolon.
• * Participants with intestinal failure or short bowel syndrome.
• * Presence of symptomatic colonic or small bowel obstruction, confirmed by objective radiographic or endoscopic evidence of a stricture with resulting obstruction (dilation of the colon or small bowel proximal to the stricture on barium radiograph or an inability to traverse the stricture at endoscopy).
• * History of extensive colonic resection (eg, less than 30 cm of colon remaining) that would prevent adequate evaluation of the effect of study agent on clinical disease activity.
• * History of colonic mucosal dysplasia or presence of adenomatous colonic polyps not removed OR presence of colonic mucosal dysplasia or adenomatous colonic polyps not removed during colonoscopy at screening visit.
• * If the participant has extensive colitis for ≥8 years or disease limited to left side of colon (ie, distal to splenic flexure) for \>10 years, regardless of age, a colonoscopy within 1 year of the screening visit is required to survey for dysplasia. Participants with dysplasia or cancer identified on biopsies will be excluded.
• * Diagnosis of indeterminate colitis, microscopic colitis, ischemic colitis, or Crohn's disease or clinical findings suggestive of Crohn's disease.