Colon to Rectum
Aliment Pharmacol Ther. 2023;57(1):81–93
Randomized clinical trial: Efficacy and safety of the live biotherapeutic product MRx1234 in patients with irritable bowel syndrome
Background: MRx1234 is a live biotherapeutic product that contains a strain of Blautia hydrogenotrophica. It is in development for the treatment of irritable bowel syndrome (IBS).
Aims: To assess the efficacy and safety of MRx1234 in patients with IBS with predominant constipation (IBS-C) or diarrhea (IBS-D).
Methods: The authors conducted a multicenter, randomized, double-blind, placebo-controlled, phase 2 trial. Patients aged 18–70 years in 2 parallel cohorts (IBS-C; IBS-D) were randomized (1:1) to MRx1234 or placebo for 8 weeks. The primary efficacy end point was overall responder rate – a composite of improved bowel habit (IBS-C: stool frequency; IBS-D: stool consistency) and abdominal pain intensity – for ≥ 50% of the treatment period in each cohort. Statistical testing was at a 1-sided 0.10 significance level.
Results: Of 366 randomized patients (164 IBS-C; 202 IBS-D), 365 received any study medication (177 MRx1234, 188 placebo). Numerically, although not statistically significantly different, more patients who received MRx1234 than placebo were overall responders in the IBS-C (25.0% vs. 17.1%) and IBS-D (23.4% vs. 17.8%) cohorts. Similar results were observed in the additional combined cohort analysis (24.1% vs. 17.5%; p = 0.063). For the components of the primary end point, significantly more patients on MRx1234 than placebo reported improvement in bowel habit in the IBS-C, IBS-D and combined cohorts, while improvements in abdominal pain were observed in each cohort. The safety profile of MRx1234 was similar to placebo.
Conclusions: MRx1234 has the potential to become a novel, safe treatment option for patients with irritable bowel syndrome with predominant constipation (IBS-C) or diarrhea (IBS-D), and for those who have mixed symptoms or transition between subtypes.