AIM-IBD: A Phase 2b Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial of a Microbiome-Targeted Food Supplement Versus Placebo in Adults With Mild-to-Moderate, Objectively Active Ulcerative Colitis
This Phase 2b randomized, double-blind, placebo-controlled, multicenter trial will evaluate the efficacy and safety of a once-daily oral microbiome-targeted food supplement compared with matching placebo in adults with mild-to-moderate, objectively active ulcerative colitis. The supplement is food-grade and is intended for use either alongside stable standard ulcerative colitis therapy (5-aminosalicylic acid/mesalamine) or in participants not currently on any inflammatory bowel disease therapy. Approximately 162 participants will be enrolled at university hospital centers in Turkey and randomized in a 1:1 ratio to receive either the food supplement or matching placebo for 24 weeks, in addition to their existing background therapy as defined by eligibility. The primary objective is to determine whether the supplement increases the proportion of participants achieving composite clinical-plus-biochemical remission at Week 24. This composite endpoint requires absence of rectal bleeding, improvement in stool frequency, fecal calprotectin ≤250 micrograms/g, and no rescue therapy, prohibited treatment escalation, ulcerative colitis-related hospitalization, colectomy, or discontinuation for lack of efficacy before Week 24. Key secondary endpoints include endoscopic improvement, deep biochemical remission, change in fecal calprotectin, change in partial Mayo score, corticosteroid-free composite remission, change in quality of life, change in C-reactive protein, time to treatment failure, and safety. Exploratory analyses will assess stool microbiome composition, eukaryotic carriage including Blastocystis, and associations between baseline microbiome features and treatment response.
• Adults aged 18 to 75 years inclusive at screening.
• Documented diagnosis of ulcerative colitis established at least 3 months before screening, based on standard clinical, endoscopic, and histologic criteria.
• Mild-to-moderate active ulcerative colitis defined by a partial Mayo score of 4 to 8 at screening.
• Rectal bleeding subscore of at least 1 at screening.
• Objective intestinal inflammation defined by fecal calprotectin of at least 250 micrograms per gram at screening, measured by the central laboratory or by a validated harmonized assay.
• Eligible disease extent: left-sided colitis or extensive/pancolitis. Proctosigmoiditis is eligible if inflammation extends beyond isolated proctitis and is measurable by study endoscopy. Isolated ulcerative proctitis (E1 only) is eligible only within a prespecified cap not exceeding 10 percent of total enrollment.
• Either no current ulcerative colitis-directed therapy, or stable oral and/or rectal 5-aminosalicylate (5-ASA, mesalamine) therapy at unchanged dose for at least 8 weeks before randomization, with intent to continue at the same unchanged dose through Week 24 unless rescue therapy is clinically required.
• Able and willing to provide written informed consent.
• Able and willing to comply with study visits, stool sampling, endoscopy, medication restrictions, and diary/patient-reported outcome completion.
⁃ Participants of childbearing potential must agree to use a highly effective method of contraception during dosing and for at least 4 weeks after the last dose, in accordance with EMA/CTFG guidance and local ethics requirements.