Larazotide

WHAT IT IS

Larazotide acetate is a synthetic peptide designed to act locally in the gut, where it is intended to tighten the junctions between intestinal cells and limit paracellular permeability, sometimes loosely described as gut leakiness.

It was developed specifically as a drug candidate for celiac disease, a condition in which gluten exposure triggers an immune reaction and intestinal damage in genetically susceptible people. Unlike many research peptides discussed elsewhere on this site, larazotide has a long clinical development history spanning more than 15 years and multiple company sponsors.

It is not a dietary supplement or a cosmetic ingredient. It was studied as a prescription drug candidate meant to be used alongside, not instead of, a gluten-free diet.

WHAT RESEARCHERS ARE STUDYING IT FOR

Clinical development of larazotide has focused on:

• Reducing persistent gastrointestinal symptoms in celiac disease patients who remain symptomatic despite a gluten-free diet
• Limiting intestinal permeability increases triggered by inadvertent gluten exposure
• Use as an add-on therapy alongside dietary gluten avoidance, not a replacement for it
• Patient-reported outcome measures such as abdominal pain and symptom severity scores

PROPOSED BIOLOGICAL MECHANISMS

The working hypothesis is that larazotide regulates tight junction proteins between the cells lining the small intestine, reducing the passage of gluten peptide fragments across the intestinal barrier and into deeper tissue where they can trigger an immune response.

Because it is designed to act within the gut lumen rather than being absorbed systemically, larazotide is taken orally as an enteric-coated capsule intended to release in the intestine.

This mechanism is plausible and grounded in real biology of the celiac disease process, but a plausible mechanism does not guarantee that a drug produces a meaningful clinical benefit, which is exactly what its Phase 3 program was designed to test.

AREAS OF RESEARCH INTEREST

• Whether reducing intestinal permeability meaningfully improves patient-reported symptoms
• Which subgroup of celiac disease patients, if any, might respond to the drug
• How to measure clinically meaningful benefit in a condition where symptoms can be variable
• Whether earlier positive Phase 2 signals can be reconciled with the negative Phase 3 outcome

WHAT THE EVIDENCE CURRENTLY SUGGESTS

Larazotide has been studied in multiple human clinical trials over more than 15 years, more than almost any peptide discussed in this library. Earlier Phase 2 studies produced some encouraging signals on symptom scores in celiac disease patients on a gluten-free diet.

In 2022, the sponsor, 9 Meters Biopharma, terminated its pivotal Phase 3 trial (CedLara, NCT03569007) after a pre-specified interim analysis found that the number of additional patients needed to detect a statistically significant effect was too large to justify continuing the study. The trial's efficacy results did not support continuation.

That outcome does not prove larazotide has zero biological effect, but it does mean the compound has not demonstrated the level of benefit needed for approval, and its further clinical development for celiac disease has stalled since. FDA status: Larazotide is not FDA-approved and is not currently in active Phase 3 development for celiac disease.