Larazotide
Gut Health / Tight Junction Regulatorinvestigational (Phase III)Also known as: Larazotide acetate, AT-1001, INN-202
A synthetic octapeptide that regulates intestinal tight junctions, developed as the first drug to target intestinal permeability ('leaky gut') in celiac disease and other conditions.
Overview
Larazotide acetate is a synthetic 8-amino acid peptide derived from Vibrio cholerae zonula occludens toxin (Zot) that acts as a tight junction regulator. It was developed by Innovate Biopharmaceuticals (now 9 Meters Biopharma) as a first-in-class oral therapy targeting intestinal permeability for celiac disease. Unlike a gluten-free diet, which avoids the trigger, larazotide addresses the downstream pathological mechanism โ the opening of intestinal tight junctions that allows gluten peptides and other antigens to cross the epithelial barrier and trigger immune responses. In Phase II and III clinical trials, larazotide reduced celiac disease symptoms in patients already on a gluten-free diet who continued to have residual symptoms. It acts locally in the gut lumen with minimal systemic absorption, giving it an excellent safety profile. Beyond celiac disease, larazotide has potential applications for other conditions associated with increased intestinal permeability, including inflammatory bowel disease, IBS, type 1 diabetes, and environmental enteropathy.
Mechanism of Action
Larazotide acts on intestinal tight junctions: (1) Blocks the zonulin receptor pathway that triggers tight junction disassembly; (2) Prevents gliadin-induced (and other antigen-induced) opening of paracellular pathways; (3) Maintains the integrity of the zonula occludens protein complex (ZO-1, occludin, claudins); (4) Reduces intestinal permeability to macromolecules including gluten fragments; (5) Acts locally in the gut lumen โ minimal systemic absorption; (6) Reduces downstream immune activation by preventing antigen translocation across the epithelium; (7) Does not digest gluten or prevent its initial contact with the mucosa.
Molecular Formula
C40H63N9O11
Molecular Weight
834.00 g/mol
Sequence
Gly-Gly-Val-Leu-Val-Gln-Pro-Gly
Dosage Protocols
Dose Range
0.25mg โ 1.0mg
Frequency
Three times daily (before meals)
Route
oral
Cycle Length
Ongoing
Taken 15 minutes before each meal. The 0.5mg TID dose showed optimal efficacy in Phase IIb trials. Acts locally in the gut โ not systemically absorbed. Must be used alongside a gluten-free diet, not as a replacement.
Source: Phase II/III clinical trial protocols
Side Effects
| Effect | Severity |
|---|---|
| Headache | mild |
| GI symptoms | mild |
| Upper respiratory infection | mild |
Pros & Cons
First-in-class mechanism targeting intestinal permeability directly โ addresses root pathophysiology of leaky gut
Oral administration with local gut action and minimal systemic absorption โ excellent safety profile
Human clinical trial data (Phase II/III) demonstrating efficacy in reducing celiac symptoms
Potential broad applicability to multiple conditions involving increased intestinal permeability
Not yet FDA-approved โ still in clinical development pipeline
Adjunctive therapy only โ does not replace gluten-free diet for celiac patients
Very limited availability as a research compound
Phase III results were mixed โ primary endpoints not consistently met across trials
Research Studies
Legal Status
Not FDA-approved. Phase III clinical trials completed for celiac disease (as of 2024). Not yet available by prescription. Available as a research compound from some suppliers.
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