Microbiotica, a clinical-stage biopharma company developing a pipeline of oral precision microbiome medicines called live biotherapeutic products (LBPs), announces positive results in its Phase 1b First-in-Human trial, COMPOSER-1, of MB310 in ulcerative colitis (UC) patients.
The study of MB310 (an investigational precision microbiome medicine taken orally once daily) met its primary and secondary study objectives being safe and well tolerated, with successful engraftment of the MB310 bacteria and statistically significant improvements in efficacy parameters compared with placebo at the end of study assessments. Notably, MB310 achieved clinical remission that was indicative of disease modification.
Professor Herbert Tilg, Medical University, Innsbruck, Austria and Scientific Advisory Board member, said,
“These early results are encouraging. Ulcerative colitis is a debilitating inflammatory bowel disease that affects over 1.4 million people globally. By dosing with healthy bacterial species shown to be associated with clinical improvements in ulcerative colitis, MB310 has the potential to be a transformative medicine that could be disease modifying and change the underlying natural pathology of the condition.”
Study design
The COMPOSER-1 randomised, placebo-controlled, double-blind, clinical trial recruited 29 adult patients at clinical centres in five countries across Europe (UK, Austria, Bulgaria, Poland and Spain), with active, mild-to-moderate UC. The patients took two capsules of study medication (active or matched placebo) once a day for 12 weeks in addition to their standard of care medication, with a 12-week follow-up period. (Study identifiers: NCT06582264; 2023-507376-50).
Study results
The study met its primary objective, demonstrating that MB310 had a similar safety profile as placebo. The bacterial strains within MB310 successfully engrafted into patients as early as the first week into treatment. All eight bacteria of the MB310 consortium persisted throughout the 3-month treatment period and were also maintained during the 3-month post dosing follow-up period. This indicates patients had full exposure to MB310 for the entire study, including both dosing and 3-month follow-up period.
Initial signals of efficacy were measured using standard clinical endpoints, including assessment of clinical signs and symptoms, endoscopy, histology and inflammatory biomarkers. MB310 demonstrated:
- Improvement in remission for patients on MB310 (12 out of 19, i.e., 63%) compared with those on placebo (3 out of 10, i.e., 30%) as measured by partial Mayo score (the standard disease activity index)
- All 12 patients who completed MB310 treatment and entered the follow-up stage were in clinical remission at the end of study. Notably rectal bleeding, a symptom known to be of importance in UC, was completely resolved
- Improvement of histological markers of disease activity, and particularly those relating to gut epithelial barrier integrity compared to baseline and placebo
- Improvement of the key biomarker of active bowel inflammation, faecal calprotectin, consistent with the observed improvement in clinical signs and symptoms compared to placebo
- Withdrawal rates similar in both arms
These data are supportive of preclinical studies that have demonstrated that the MB310 consortium acts via at least three independent mechanisms that are central to the pathology of UC: promoting the healing of the damaged gut epithelial barrier; regulating the balance of cytokines that are inflammatory (TNF) and immune-modulatory (IL-10); and inducing a regulatory T-cell response.
Dr Robert Tansley, Microbiotica’s Chief Medical Officer, said,
“We are encouraged by these positive data from our Phase 1b study of MB310 in ulcerative colitis. Our clinic-led approach to the discovery of live biotherapeutic products results in a defined, consistent and reproducible product, which we believe has the best chance of producing clinical benefit by becoming safely established in the microbiome of patients and addressing key underlying causes of ulcerative colitis.
“Our first-in-human study has demonstrated safety and tolerability together with encouraging efficacy data. It supports the hypothesis that MB310 has the potential to deliver disease modifying, long lasting remission with an excellent tolerability profile.
“The highly encouraging clinical remission rates at 6 months, is more impressive than any ulcerative colitis therapy I have seen to date. If confirmed in larger studies, MB310 has the potential to transform the management of ulcerative colitis by addressing a key factor behind the pathophysiology of the disease not currently treated. We are planning our Phase 2/3 studies where such potential is evaluated in combination with standard of care therapies.”
Tim Sharpington, CEO of Microbiotica, added,
“We are very excited about these promising results. MB310 has the potential to be a new, differentiated treatment modality for patients with ulcerative colitis, offering the hope of long-lasting disease remission without side effects.
“The study results also provide validation of our clinic-first microbiome discovery platform which brings new precision in the identification of bacterial strains associated positive outcomes from clinical trial data. Combined with our increased understanding of the mechanisms by which our microbiome interact with host cells, this gives us the opportunity to design differentiated, precision microbiome medicines in different disease settings.
“During 2026, we will explore partnering and financing options to determine the best route to fund our products through later studies and towards commercialisation.”
Future plans
Microbiotica is conducting additional analysis of COMPOSER-1 data, to further explore the impact of MB310 and to inform the design of the adaptive Phase 2/3 study. It is anticipated that this study will explore the disease modifying ‘slower-onset longer-acting’ potential of MB310 in combination with anti-inflammatory and/or immuno-modulatory induction agents.
About Ulcerative Colitis – MB310 and the COMPOSER-1 study
Ulcerative colitis, an inflammatory bowel disease, is a debilitating disease that affects over 1.4 million people globally. The gut microbiome is now understood to contribute significantly to the disease pathology but is not targeted by current therapies. The rapid increase in incidence and prevalence of UC in Europe and North America in the 20th century as well as the ongoing increase in newly industrialised countries is believed to be associated with detrimental changes to the microbiome resulting from increased processed foods, changing diet, increased use of antibiotics and improved hygiene.
MB310, an investigational microbiome medicine, has been developed as an oral capsule, dosed once daily, containing a defined consortium of eight live gut commensal bacterial strains. It is designed to deliver long-term remission to UC patients, without immunosuppression or unwanted side-effects. The bacterial strains in MB310 were identified by analysing clinical and microbiome data from a faecal microbiota transplant (FMT) study in UC patients carried out with collaborators at the University of Adelaide. The results demonstrated the ability of a microbiome therapy to induce remission in UC with an excellent tolerability profile. Microbiotica‘s analysis identified the engrafting bacteria associated with clinical response, leading to the development of MB310 as an LBP.
The COMPOSER-1, first-in-human study investigated the safety, tolerability, and initial signals of efficacy of MB310 in a randomised, placebo-controlled, double-blind, clinical trial. The degree to which the bacteria within MB310 successfully engraft into patients’ intestinal microbial community was measured. The study enrolled 29 patients with active, mild-to-moderate UC, who took two capsules of study medication (active or matched placebo) once a day for 12 weeks in addition to their standard of care medication, with a 12-week follow-up period. (Study identifiers: NCT06582264; 2023-507376-50). Positive data readout reported in early 2026 demonstrated that MB310 met primary and secondary study objectives being safe and well tolerated, with successful engraftment of the MB310 bacteria and statistically significant improvements in efficacy parameters. The study achieved clinical remission indicative of disease modification.