A Phase 1b Trial to Evaluate the Safety of MB310 in Patients With Active, Mild-to-Moderate Ulcerative Colitis (COMPOSER-1)

A Phase 1b, Randomized, Placebo-Controlled, Double-Blind Study to Evaluate Safety, Engraftment, and Initial Signs of Clinical Activity of MB310 in Patients With Active, Mild-to-Moderate Ulcerative Colitis

A Phase 1b study to evaluate the safety and tolerability of MB310 given to patients who have active mild-to-moderate ulcerative colitis.

Study Overview

• Status: Completed
• Conditions: Ulcerative Colitis
• Intervention / Treatment: Drug: Vancomycin; Biological: MB310; Other: Placebo

• Study Type: Interventional
• Enrollment (Actual): 29
• Phase: Phase 1

Contacts and Locations

Study Locations

• Austria
  • Innsbruck, Austria
    • Medizinische Universitaet Innsbruck
  • Klagenfurt, Austria
    • Klinikum Klagenfurt am Woerthersee
  • Salzburg, Austria
    • Uniklinikum Salzburg
  • Vienna, Austria
    • Medizinische Universitaet Wien
• Bulgaria
  • Sofia, Bulgaria
    • Acibadem City Clinic, Tokuda Hospital
  • Sofia, Bulgaria
    • Diagnostic Consulting Center Convex EOOD
  • Sofia, Bulgaria
    • Medical Center Rusemed EOOD
  • Stara Zagora, Bulgaria
    • University Multiprofile Hospital for Active Treatment
  • Varna, Bulgaria
    • Diagnostic-Consulting Center
• Poland
  • Bydgoszcz, Poland
    • Centrum Medyczne Kermed
  • Rzeszów, Poland
    • Korczowski Bartosz, Gabinet Lekarski
  • Warsaw, Poland
    • Panstwowy Instytut Medyczny MSWiA - Klinika Gastroenterologi i Chorob Wewnetrznych
  • Warsaw, Poland
    • Warsaw IBD Point
  • Warsaw, Poland
    • Wojskowy Instytut Medyczny - Panstwowy Instytut Badawczy, Klinika Gastroenterologii i Chorob Wewnetrznych
• United Kingdom
  • Birmingham, United Kingdom
    • University Hospital Birmingham
  • Cambridge, United Kingdom
    • Addenbrooke's Hospital
  • London, United Kingdom
    • St George's Hospital
  • Newcastle, United Kingdom
    • Royal Victoria Infirmary

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

• Must be aged 18 to 70 years, inclusive, at the time of signing informed consent;
• Must have newly diagnosed or a history of recurrent UC based on clinical, endoscopic, and histological assessments;
• Must have active, mild-to-moderate UC as defined by the Modified Mayo Score (MMS) of ≥4 and ≤7, and an Endoscopic Subscore of ≤2 in the most affected area proximally ≥15 cm from anal verge;
• Male patients, and female patients of childbearing potential who are at risk of pregnancy, must agree to use a highly effective method of birth control
• Female patients must not be pregnant or breastfeeding;
• Male patients must agree to abstain from sperm donation;
• Must be able to understand and comply with the Protocol requirements; and
• Must be willing and able to provide written informed consent at Screening (Visit 1).

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

• Disease limited to proctitis <15 cm from anal verge;
• Short bowel or malabsorption syndromes;
• Prior intestinal or colon resection surgery (with exception of cholecystectomy or appendectomy);
• Severe/fulminant UC;
• Other forms of inflammatory bowel disease including diagnostic uncertainty by the Investigator, or functional gastrointestinal disorders;
• Positive stool test for parasites, bacterial pathogens, or Clostridium difficile;

• Use of any of the following treatments:

  • Oral 5-ASA products at a dose >3.0 g per day (unless the use is currently stable and anticipated to remain stable during the study);
  • Aspirin or other nonsteroidal anti-inflammatory drugs (except aspirin for cardioprotective reasons at a dose of ≤325 mg per day);
  • Loperamide and other antidiarrheal agents or probiotics;
  • Antibiotics or other antibacterial treatment (unless an ophthalmic or otic antibiotic preparation, or a topical antibiotic for skin infection);
  • Faecal Matter Transplant (FMT) or administration of Vowst®, Rebiotix®, or other Live Biotherapeutic Product (LBP);
  • Intravenous or intramuscular corticosteroids;
  • Oral corticosteroids >10 mg prednisolone or equivalent per day;
  • Any drugs formulated for rectal administration and/or interventions;
  • Immunomodulating or immunosuppressing drugs (unless the use is currently stable and anticipated to remain stable during the study);
  • Biologics, ozanimod, etrasimod, tofacitinib, filgotinib, or upadacitinib; or
  • Proton pump inhibitors (PPIs) or H2 blockers.
• Patients whose disease has not responded to or lost response to 2 or more advanced therapies (biologics or small molecules);
• Significant liver impairment;
• Concurrent primary sclerosing cholangitis;
• Clinically significant hematological function abnormalities;
• Known hypersensitivity, intolerance, or contraindication to oral vancomycin, MB310, and/or any excipients;
• History of, or known malignancy (unless adequately treated (i.e., cured) basal cell carcinoma or squamous cell carcinoma of the skin, or cervical intraepithelial neoplasia or carcinoma in situ of the cervix with no evidence of recurrence within 5 years prior to Screening);
• Any infectious disease (HIV is allowed where certain protocol-specified criteria are met);
• Significant cardiovascular condition;
• Involvement in another clinical study (unless observational) within 4 weeks of Screening from the last dose of study drug or 5 half-lives, whichever is longer; or
• Any other clinically relevant or poorly controlled, unstable condition that would confound study endpoints or adversely affect patient safety or compliance.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vancomycin preconditioning followed by MB310; Vancomycin 125mg QID for 5 days plus 2 day wash-out prior to receiving MB310 PO (2 capsules once a day) for 12 weeks	Drug: Vancomycin; Antibiotic; Biological: MB310; Live bacterial therapeutic for oral administration
Placebo Comparator: Vancomycin preconditioning followed by Placebo; Vancomycin 125mg QID for 5 days plus 2 day wash-out prior to receiving MB310-matching placebo PO (2 capsules once a day) for 12 weeks	Drug: Vancomycin; Antibiotic; Other: Placebo; MB310-matching placebo for oral administration

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incidence and causality of adverse events (AEs), treatment-emergent AES, AEs of Scientific Interest and SAEs	From Visit 1 to End of Follow-Up (12 weeks after the last dose of study treatment)
Incidence of treatment-emergent clinically significant changes in laboratory parameters, based on haematology, clinical chemistry, and urinalysis test results	From Visit 1 to End of Follow-Up (12 weeks after the last dose of study treatment)
Incidence of treatment-emergent clinically significant changes in 12-lead ECG parameters, vital signs, and physical examination	From Visit 1 to End of Follow-Up (12 weeks after the last dose of study treatment)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of patients achieving clinical remission at Day 91	Clinical remission defined as a Modified Mayo Score (MMS) 0 to 2 with endoscopic subscore of 0 or 1	Day 91
Percentage of patients achieving steroid-free remission at Day 91	No steroid exposure at Day 91 with a MMS score of 0 to 2 with endoscopic subscore of 0 or 1	Day 91
Percentage of patients achieving persistent steroid-free remission at Day 91	No steroid exposure between Day 64 and Day 91 with a MMS score of 0 to 2 with endoscopic subscore of 0 or 1	Day 64 to Day 91
Percentage of patients achieving clinical response at Day 91	Clinical response defined as a decrease in MMS by 2 or more points and at least a 30% reduction from baseline, and a decrease in the rectal bleeding subscore of 1 or more or an absolute rectal bleeding subscore of 0 or 1	Day 91
Percentage of patients achieving endoscopic improvement at Day 91	Endoscopic improvement is defined as a decrease in MMS endoscopic subscore by 1 or more point from baseline	Day 91
Percentage of patients who achieve clinical improvement at Day 64 (Visit 10) and Day 91 (Visit 11)	Clinical improvement defined as a decrease in Partial Mayo Score (pMayo) of 2 or more points from baseline	Day 91
Time to clinical improvement	Clinical improvement defined as a decrease in Partial Mayo Score (pMayo) of 2 or more points from baseline	End of Follow-Up (12 weeks after the last dose of study treatment)
Engraftment of MB310 bacteria into patients' intestinal microbial community	Measurement of MB310 strain colonisation in stool samples using a qPCR-based approach.	Up to End of Follow-Up (12 weeks after the last dose of study treatment)

Collaborators and Investigators

• Sponsor: Microbiotica Ltd

Study record dates

Study Major Dates

• Study Start (Actual): September 27, 2024
• Primary Completion (Actual): January 8, 2026
• Study Completion (Actual): January 8, 2026

Study Registration Dates

• First Submitted: August 19, 2024
• First Submitted That Met QC Criteria: August 30, 2024
• First Posted (Actual): September 3, 2024

Study Record Updates

• Last Update Posted (Actual): February 17, 2026
• Last Update Submitted That Met QC Criteria: February 16, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Intestinal Diseases; Digestive System Diseases; Gastrointestinal Diseases; Colonic Diseases; Gastroenteritis; Inflammatory Bowel Diseases; Colitis; Colitis, Ulcerative; Peptides; Amino Acids, Peptides, and Proteins; Carbohydrates; Glycoconjugates; Glycopeptides; Vancomycin
• Other Study ID Numbers: MB310-01; 2023-507376-50 (EudraCT Number)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No