Immune & defense TREM-1 inhibitor peptide
Nangibotide
Regulatory status
Status at a glance
503A compounding status
Not nominated
We found no pending nomination for the 503A bulks list. Unless the substance has another legal pathway (for example, a USP monograph or use in an FDA-approved drug), 503A pharmacies generally may not compound with it.
- FDA approval
- Not FDA-approved for any use
- 503B outsourcing
- Not determined
- Anti-doping (WADA)
- Not on the WADA Prohibited List
- DEA schedule
- Not a controlled substance
About peptide status
Most peptides discussed here are not FDA-approved for any use, and products labeled “research use only” are not for human use. Removal from Category 2 does not authorize compounding. PCAC votes are non-binding recommendations; FDA and HHS make the final decisions.
This is not medical or legal advice, and we do not publish dosing, sourcing or reconstitution information. Talk with a licensed clinician before using any peptide.
If you think you are having a medical emergency, call 911.
Key takeaway
Nangibotide is an investigational peptide that inhibits the inflammatory receptor TREM-1, developed by Inotrem as an intravenous treatment for septic shock. Its Phase 2b trial did not meet its primary endpoint, though a signal appeared in a subgroup of patients with high levels of a related biomarker. As of 2026 it is not approved.
At a glance
- FDA status
- Investigational peptide, not approved by the FDA
- What it is
- TREM-1 inhibitor given by intravenous infusion for septic shock
- Research
- Phase 2b trial (ASTONISH) did not meet its primary endpoint
- Subgroup signal
- Appeared only in a biomarker-defined subgroup
- Evidence strength
- Low research
Summary
Nangibotide is an investigational peptide that blocks TREM-1 to calm inflammation in septic shock. Learn how it works and where its trial evidence stands.
What is nangibotide?
Nangibotide (also known as LR12 or Motrem) is an experimental peptide of twelve amino acids that inhibits TREM-1, a receptor that amplifies inflammation. It is developed by Inotrem and given by intravenous infusion, studied for septic shock, a life-threatening condition in which infection triggers a dangerous drop in blood pressure and organ dysfunction. It is investigational and not approved.
How does it work?
Nangibotide acts as a decoy that interferes with TREM-1 (Triggering Receptor Expressed on Myeloid cells-1). TREM-1 normally amplifies the immune system's inflammatory response, and in septic shock this amplification can become harmful. By blocking TREM-1 engagement, nangibotide is intended to dampen the excessive release of inflammatory signals. A related marker, soluble TREM-1, is used to identify patients whose TREM-1 pathway is most activated. This describes the mechanism, separate from the trial outcome below.
Is it FDA-approved?
Safety note
Status: Investigational peptide, not approved by the FDA
Category: In clinical trials · Primary body area: Immune & defense
No. Nangibotide is investigational and not approved. Development has continued toward a possible Phase 3 using a biomarker-enrichment strategy to select patients.
What does the research show?
Editor’s note
Evidence strength: Low research
The controlled Phase 2b trial did not meet its primary endpoint, with a positive signal confined to a biomarker-defined subgroup that remains unconfirmed.
The controlled evidence did not meet its goal. According to PubMed, the Phase 2b ASTONISH trial in septic shock did not meet its primary endpoint, an improvement in organ-failure score:
| Patient group | Organ-failure score result |
|---|---|
| Predefined high-biomarker group | Improvement not statistically significant |
| Overall | Improvement not statistically significant |
| Higher biomarker cutoffs only | Clinically relevant improvement, a subgroup finding that remains unconfirmed |
The company had earlier framed the result as positive, but the peer-reviewed publication states the primary outcome was not achieved. Efficacy is therefore not established.
Sources: the ASTONISH Phase 2b trial (François et al., The Lancet Respiratory Medicine, 2023, DOI: 10.1016/S2213-2600(23)00158-3), indexed on PubMed; and Inotrem program updates. This document is educational, is not medical advice or a health claim, and is not an offer to sell any product.
Registered human trials
0 registered human trials on ClinicalTrials.gov that we reviewed
Sources
- [1]
Compare every peptide’s status in the peptide regulatory status database
More for Immune & defense
View all immune & defense peptides →- In clinical trials Immune & defense
Aviptadil
Aviptadil is a synthetic form of vasoactive intestinal peptide (VIP), a signaling molecule that acts on lung receptors, and it has been studied mainly for severe COVID-19 respiratory failure. In the NIH-funded TESICO trial of 461 patients, aviptadil did not beat placebo on the 90-day recovery scale (odds ratio 1.11, 95% CI 0.80 to 1.55, p = 0.54). Ninety-day mortality was 38% with aviptadil versus 36% with placebo (p = 0.78), and the trial stopped early for futility. As of 2026 it is not FDA-approved for any use.
- FDA-approved Immune & defense
Cyclosporine
Cyclosporine (also spelled ciclosporin; brands include Sandimmune, Neoral, and the eye drop Restasis) is a cyclic peptide from a fungus that suppresses the immune system, and it transformed organ transplantation when it arrived in the 1980s. It works by blocking the activation of T cells. It has been FDA-approved in the U.S. since 1983, is available in oral, intravenous, and eye-drop forms, and carries boxed warnings for the systemic versions.
- FDA-approved Immune & defense
Enfuvirtide
Enfuvirtide (formerly sold as Fuzeon) is a peptide HIV drug that blocks the virus from entering CD4 immune cells, the first of the so-called fusion inhibitors. It was used in treatment-experienced patients whose virus is no longer controlled by other antiretrovirals. It was FDA-approved in the U.S. in 2003, but Fuzeon was discontinued there in February 2025.
- Not FDA-approved Immune & defense
Ll-37
LL-37 is the body's natural antimicrobial "host-defense" peptide, intensely studied as part of the immune system and sold on the "research peptide" market for antimicrobial and immune support. Its biology is well described, but there is no approved product and no human efficacy evidence for the injected wellness use, and its effects are context-dependent. As of 2026 it is not FDA-approved.
- In clinical trials Immune & defense
Murepavadin
Murepavadin is an investigational antimicrobial peptidomimetic that targets a protein unique to Pseudomonas aeruginosa, developed by Polyphor for serious lung infections. Its intravenous Phase 3 program was halted after an unexpected rate of kidney injury, and later inhaled development did not mature. As of 2026 it is not approved.
- FDA-approved Immune & defense
Polymyxin-B-Colistin
Polymyxin B and colistin (colistin is also called polymyxin E) are older cyclic lipopeptide antibiotics that have returned to use as last-resort treatments for multidrug-resistant Gram-negative infections. They punch holes in the bacterial outer membrane but carry meaningful kidney and nerve toxicity. Both have long been FDA-approved in the U.S. and are reserved for serious infections with few other options.