Brenipatide (LY3537031) for IBS with constipation

A Phase 2, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Brenipatide in the Treatment of Adult Participants With IBS-C

This trial will test whether brenipatide (LY3537031), given by a small under-the-skin injection, helps adults with IBS-C have less belly pain and more normal bowel movements compared with a placebo.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 342 (estimated)
• Ages: 18 Years to 75 Years
• Sex: All
• Sponsor: Eli Lilly and Company (Industry-sponsored)
• Locations: 1 site (Louisville, Kentucky)
• Trial ID: NCT07545772 on ClinicalTrials.gov

What this trial studies

This Phase 2 interventional trial compares subcutaneous brenipatide (LY3537031) to placebo in participants who meet Rome IV criteria for IBS-C. Participants will be treated and followed for approximately 35 weeks with regular clinic visits and daily symptom reporting via an eDiary, including worst abdominal pain scores and Bristol Stool Form Scale entries. The protocol emphasizes safety and tolerability monitoring alongside measures of efficacy for constipation and pain. Exclusion criteria remove those with diarrhea-predominant or mixed IBS, inflammatory gastrointestinal disorders, or clinically significant gastric emptying abnormalities.

Who should consider this trial

Good fit: Adults who meet Rome IV criteria for IBS-C with more than 25% hard stools (BSFS types 1–2), less than 25% loose stools (BSFS types 6–7), and an average worst abdominal pain score ≥3 during screening are ideal candidates.

Not a fit: People with diarrhea-predominant or mixed IBS, those with inflammatory or immune-mediated GI disorders, or a known significant gastric emptying problem are unlikely to benefit or be eligible for this trial.

Why it matters

Potential benefit: If successful, brenipatide could offer a new injectable option to reduce abdominal pain and improve bowel habits in people with IBS-C.

How similar studies have performed: Some investigational peptide-based and prokinetic approaches for IBS-C have shown benefit in prior research, but injectable peptide treatments remain relatively novel and evidence is limited.

Eligibility criteria

Inclusion Criteria:

* Meets Rome IV criteria for irritable bowel syndrome-constipation (IBS-C) including having more than 25% bowel movements with Bristol Stool Form Scale (BSFS) Types 1 or 2 and less than 25% of bowel movements with BSFS Types 6 or 7
* Based on the daily eDiary collection during the screening period:

  * Have average of worst abdominal pain score of ≥3.0 on a 0-to-10-point scale during the 14 consecutive days prior to randomization

Exclusion Criteria:

* Have a diagnosis of irritable bowel syndrome (IBS) with a subtype of diarrhea, mixed IBS, or unclassified IBS by the Rome IV criteria
* Have a history of inflammatory or immune-mediated gastrointestinal disorders
* Have a known clinically significant gastric emptying abnormality

Where this trial is running

Louisville, Kentucky

• Gastroenterology Health Partners Loc. 1 — Louisville, Kentucky, United States (Recruiting)

Study contacts

• Study coordinator: Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or

Conditions Irritable Bowel Syndrome; Constipation