Inclusion 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.

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

• 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.

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.