EXL01 in the Maintenance of Steroid-induced Clinical Response/Remission in Participants With Mild to Moderate Crohn's Disease

Key Inclusion Criteria: Must meet all of the following criteria at the start of the Induction Period: * Male or female aged ≥18 years and \<75 years at the time of providing informed consent. * A diagnosis of CD with ileal involvement for at least 3 months prior to Screening. * A CDAI score \>180 and \<350. * Part B only: Active mucosal inflammation. Key Exclusion Criteria: * Stricture with obstructive syndrome \<3 months prior to Screening. * Stenosis making endoscopic access to the terminal ileum difficult. * Received treatment with high dose corticosteroid (≥40 mg prednisone daily) for \>5 weeks within 3 months prior to Screening. * Part B only: Received \>3 prior biologic treatments or JAK inhibitors for CD including infliximab, ustekinumab, vedolizumab, adalimumab, certolizumab, risankizumab, and upadacitinib. * Major surgery or significant trauma ≤4 weeks prior to Screening. * Small bowel resection \>1 m in total or clinical manifestations of short bowel syndrome. * Current stoma (ileostomy or a colostomy) or had a stoma in the last 6 months or any other intraabdominal surgery within 3 months prior to Screening. * Started or stopped immunosuppressive therapy (thiopurine, methotrexate, tacrolimus, or other classical immunosuppressant) within 3 months prior to Screening. * Received faecal microbial transplant within 3 months prior to Screening. * Systemic infection or other serious infection requiring systemic treatment within 30 days prior to Screening. * Pregnant, breastfeeding, or expecting to conceive during the study.