Key inclusion criteria: * Presents with signs or symptoms of celiac disease (CD) for at least 3 months prior to assessment. * Has a CDAI score of 220 to 450, with a mean daily stool subscore ≥4 points or a mean daily abdominal pain subscore ≥2 points. * Has an SES-CD score ≥6 (or an SES-CD score ≥4 if CD is isolated to the ileum). * Demonstrated inadequate response, loss of response, or intolerance to at least one of the following treatments: corticosteroids, immunosuppressants (e.g., azathioprine, 6-mercaptopurine, methotrexate), or advanced therapies for CD (e.g., biologics, Janus kinase [JAK] inhibitors, applicable investigational products). * Agrees to comply with the study guidelines and requirements. * Is able to provide signed informed consent. Key exclusion criteria: * Diagnosed with indeterminate colitis, microscopic colitis, ischemic colitis, radiation colitis, or ulcerative colitis (UC), or has clinical findings suggestive of UC * Has isolated Crohn's disease in the oral cavity, stomach, duodenum, jejunum, or perianal region, without colonic or ileal involvement * Has had extensive bowel resection (>100 cm), and/or more than 3 resections, and/or has a known diagnosis of short bowel syndrome * Currently receiving total parenteral nutrition, tube feeding, or a formula diet * Has positive findings on a subjective neurological screening questionnaire * Has a clinically significant, severe, and unstable concurrent comorbidity * Prior treatment with vedolizumab or other approved or investigational integrin inhibitors * Currently participating in any other interventional study or has received any investigational therapy within the past 30 days * Prior exposure to MORF-057 and/or known hypersensitivity to drugs with a mechanism similar to MORF-057 * Unable to attend visits of the study or comply with the study procedures