EnteroBiotix has dosed the first patient in its Phase 2b RISE trial evaluating EBX-102-02 as a potential treatment for moderate-to-severe irritable bowel syndrome with constipation (IBS-C).

The study marks the next stage in the clinical development of the company’s lead investigational microbiome therapeutic, which is designed to restore gut microbial function in patients with IBS-C.

RISE, which stands for Restoring Intestinal Symbiosis for Efficacy in IBS, is a randomised, double-blind, placebo-controlled Phase 2b trial expected to enrol around 300 patients across seven sites in the UK.

The trial will evaluate the efficacy, safety and tolerability of EBX-102-02 in patients with moderate-to-severe IBS-C. Researchers will assess outcomes including abdominal pain, bowel habits and quality of life, while exploratory analyses will examine microbial engraftment, methane breath testing and the therapy’s potential mechanism of action.

The study follows positive results from the company’s earlier Phase 2a TrIuMPH trial, which evaluated EBX-102-02 in patients with IBS-C and irritable bowel syndrome with diarrhoea (IBS-D). According to EnteroBiotix, the earlier study demonstrated clinically meaningful improvements in symptom severity, abdominal pain, bowel habits and quality of life, together with increased microbiome diversity.

Mr Paul Goldsmith, consultant general surgeon at Manchester University NHS Foundation Trust and chief investigator of the RISE study, said: “IBS-C can be a highly burdensome condition, with many patients continuing to experience abdominal pain, bloating and constipation despite available treatment options. EBX-102-02 represents a novel investigational approach that is designed to modulate the gut microbial ecosystem, which is increasingly recognised as an important area of interest in IBS. The RISE study builds on encouraging Phase 2a clinical signals and will help evaluate whether this approach can deliver meaningful benefit for patients living with IBS-C.”

Professor Yan Yiannakou, consultant neurogastroenterologist at County Durham and Darlington NHS Foundation Trust, said: “There is growing evidence that disruption of the gut microbiome plays an important role in the pathophysiology of IBS-C. While existing therapies can improve symptoms for some patients, many continue to experience a substantial burden of disease and remain dissatisfied with available treatment options. EBX-102-02 represents a fundamentally different therapeutic approach, seeking to address dysfunction in the gut microbial ecosystem rather than only stimulate bowel activity. The RISE study is therefore an important clinical trial, and its results will be of considerable interest to clinicians and patients.”

Dr James McIlroy, chief executive officer of EnteroBiotix, said: “Dosing the first patient in RISE is an important step towards evaluating the potential of EBX-102-02 to address the underlying biology of IBS-C. The trial reflects our commitment to building a leading position in full-spectrum microbiome therapeutics for high-burden gastrointestinal diseases. We are grateful to the patients, investigators and clinical teams supporting the study and look forward to advancing this important programme.”

IBS-C affects millions of people worldwide and is characterised by abdominal pain, bloating and constipation. Although several treatments are available, many patients continue to experience persistent symptoms, prompting interest in new therapeutic approaches targeting the gut microbiome rather than symptoms alone.