This is a Phase 2b randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of three active dose regimens of MORF-057 in adult patients with moderately to severely active Ulcerative Colitis (UC).

This is a Phase 2b randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of three active dose regimens of MORF-057 plus a placebo regimen in study participants with moderately to severely active UC. After completion of the 12-week Induction Period, participants may be switched to a different active MORF-057 regimen during the Maintenance Period. Those randomized into the placebo group in the Induction Period will be switched to receive an active MORF-057 regimen during the Maintenance Period.

Inclusion Criteria:

• Has signs/symptoms of moderate to severe UC for at least 3 months prior to Screening
• Has evidence of UC extending at least 15 cm from the anal verge
• Demonstrated an inadequate response, loss of response, or intolerance to at least one of the following treatments: Oral aminosalicylates (e.g., mesalamine, sulfasalazine, olsalazine, or balsalazide), corticosteroids, immunosuppressants (e.g., azathioprine, 6-mercaptopurine, or methotrexate), advanced therapies for UC (e.g., biologic agents, Janus kinase [JAK] antagonists, or sphingosine-1-phosphate [S1P] receptor agonists)
• Subject has no prior exposure to approved or investigational anti-integrin therapies
• Agrees to abide by the study guidelines and requirements
• Capable of giving signed informed consent

Exclusion Criteria:

• Diagnosed with indeterminate colitis, microscopic colitis, ischemic colitis, radiation colitis, or Crohn's disease or has clinical findings suggestive of Crohn's disease
• Has positive findings on a subjective neurological screening questionnaire
• Has a concurrent, clinically significant, serious, unstable comorbidity
• Previous treatment with vedolizumab or other licensed or investigational integrin inhibitors
• Participation in any other interventional study or received any investigational therapy within 30 days
• Previous exposure to MORF-057 and/or a known hypersensitivity to drugs with a similar mechanism to MORF-057
• Unable to attend study visits or comply with study procedures