Nangibotide

What is Nangibotide?

Nangibotide is an investigational twelve-amino-acid peptide given by continuous intravenous infusion to critically ill patients, developed by Inotrem SA in France. It is a targeted immunomodulator rather than an antibiotic, an antiviral or a vasopressor: it does not kill anything, and it does not raise blood pressure directly. What it does is dampen one specific amplification loop in the innate immune response. The sequence is taken from nature rather than designed from scratch. TREM-like transcript-1 (TLT-1) is a platelet protein that shares a ligand with TREM-1, the receptor nangibotide targets. The twelve-residue fragment of TLT-1 known as LR12 binds that shared ligand and therefore competes with TREM-1 for it — a decoy mechanism rather than a receptor blockade. The molecule is C54H83N15O21S2 with a molecular weight of about 1343 (PubChem CID 165360157), and it has appeared in the literature under the names LR12, MOTREM and nangibotide. Its pharmacokinetics force the administration route. A first-in-man study in 27 healthy volunteers found an effective half-life of about 3 minutes and a clearance of 6.6 litres per kilogram per hour, consistent with extensive enzymatic metabolism in blood. Volumes of distribution of 16.7 and 15.9 litres indicate the drug stays largely in blood and interstitial fluid. A molecule cleared that fast cannot be given as intermittent doses, so nangibotide is infused continuously for up to five days, which confines it to the intensive care unit. It is investigational everywhere, has never been approved by any regulator, and exists only inside clinical trials.

What Nangibotide Is Investigated For

Nangibotide matters less for what it has achieved than for what it is testing. Decades of sepsis immunomodulation trials have failed — anti-TNF, anti-endotoxin, activated protein C, interleukin-1 blockade — almost always because an unselected sepsis population contains patients with opposite immunological problems, and a drug that helps one group harms another. Nangibotide is paired with a biomarker, soluble TREM-1, intended to identify in advance the patients whose TREM-1 pathway is actually overactive. If that works, it is a template; if it does not, it is another entry on a long list. The evidence so far is honestly mixed. The Phase 2a trial (49 patients) established safety, dose-proportional pharmacokinetics and the absence of anti-drug antibodies, with a non-significant signal toward improved organ failure scores that was larger in patients with high baseline soluble TREM-1. ASTONISH, the Phase 2b trial, then tested that properly: 355 patients across 42 hospitals in seven countries, randomised to low-dose nangibotide, high-dose nangibotide or placebo, with a co-primary analysis in the prespecified high soluble TREM-1 population and in everyone. It missed. In the high soluble TREM-1 group the mean difference in SOFA score from baseline to day 5 was 0.21 for the low dose (p=0.80) and 1.39 for the high dose (p=0.104); in the overall population, 0.20 (p=0.76) and 1.06 (p=0.108). Day 28 mortality showed no consistent pattern, and the investigators concluded plainly that the trial did not achieve its primary outcome. What the trial did suggest is that the threshold was set in the wrong place. High-dose nangibotide produced a clinically relevant SOFA improvement of two points or more over placebo in patients above a higher cutoff of 532 picograms per millilitre, rather than the prespecified 400. That is a post hoc refinement of a biomarker threshold on the basis of a failed trial — exactly the kind of finding that is either a genuine discovery or a statistical artefact, and the only way to tell is a prospective test. The COVID-19 trial (ESSENTIAL) is the most positive dataset in the programme and the hardest to interpret. It stopped early for slow recruitment at 220 patients, and reported improved clinical status at day 28 (64.7 versus 52.0 percent, odds ratio 1.79, 95 percent CI 1.02 to 3.14, p=0.043) and lower day 28 mortality (16.0 versus 28.0 percent, adjusted absolute improvement 12.1 percent). In the high soluble TREM-1 half, the adjusted absolute mortality reduction was 19.9 percent. These are encouraging numbers from a trial that was underpowered by design accident, in a disease whose standard of care changed underneath it.

History & Discovery

TREM-1 was identified in 2000 as a receptor on neutrophils and monocytes that was strongly upregulated in infection, and within a few years it was clear that it behaved unlike the pattern-recognition receptors around it — it recognised nothing itself, but dramatically amplified what they recognised. That made it an attractive drug target for a specific reason: blocking an amplifier should be able to reduce inflammatory injury without compromising the body's ability to detect and respond to the pathogen, which is where broad immunosuppression had always come unstuck. The work that produced nangibotide was done in Nancy, France, by Sebastien Gibot and Marc Derive, who approached the problem by looking for natural inhibitors rather than designing synthetic ones. TREM-like transcript-1, a related receptor on platelets, turned out to share a ligand with TREM-1, and a twelve-residue fragment of its extracellular domain — LR12 — was enough to act as a competitive decoy. Inotrem SA was founded to develop it, and the compound carried the development name MOTREM through its early clinical work. The clinical programme has been unusually disciplined about its own central uncertainty. Rather than running a large unselected sepsis trial — the approach that had buried a generation of immunomodulators — Inotrem built the development plan around soluble TREM-1 as a selection biomarker from the outset, partnering with Roche Diagnostics from 2017 to develop a companion assay on the Elecsys and cobas platforms. The Phase 2a trial in 2020 was explicit that its exploratory endpoints would be analysed by baseline soluble TREM-1 concentration. ASTONISH, reported in Lancet Respiratory Medicine in 2023, was the test of that strategy, and it did not pass. The COVID-19 pandemic intervened in the middle of it, producing a second trial, ESSENTIAL, which reported the programme's most encouraging numbers from its least conclusive design. In January 2024, Inotrem announced agreement with the FDA on a single Phase 3 registration trial, ACCURATE, with a revised endpoint — alive and free of organ support at day 29 — and biomarker-based selection. As of late October 2026 that trial does not appear in ClinicalTrials.gov, and a 2026 review describes nangibotide as having demonstrated feasibility and short-term safety but not having met its primary efficacy endpoint in an unselected population.

How It Works

When the body detects an infection, sensors on immune cells raise the alarm — and a separate receptor called TREM-1 turns the alarm's volume up. In severe infection that volume control gets stuck near maximum, and the resulting inflammation damages the body's own organs. Nangibotide is a short piece of a natural protein that competes for the same molecule TREM-1 needs in order to switch on. By soaking that molecule up, it turns the volume back down to something survivable, without unplugging the alarm itself.

TREM-1 is an immunoreceptor on neutrophils and monocytes that signals through the adaptor DAP12 and the ITAM pathway. Its defining feature is that it is not a pattern-recognition receptor: it does not detect pathogen-associated molecular patterns itself. Instead it amplifies signalling initiated by Toll-like receptors and other pattern-recognition receptors, substantially increasing the output of pro-inflammatory cytokines and the degree of neutrophil activation for a given initial stimulus. A 2026 review in Seminars in Respiratory and Critical Care Medicine describes it as a rheostat that tunes the magnitude of the innate response to promote antimicrobial defence while limiting inflammation-induced tissue injury, and notes that both insufficient and excessive activation are associated with adverse outcomes. Nangibotide does not bind TREM-1. It is a twelve-residue fragment, LR12, of TREM-like transcript-1, a related receptor found on platelets and megakaryocytes that shares a ligand with TREM-1. By binding that shared ligand, nangibotide acts as a competitive decoy, reducing the amount available to engage TREM-1 and so lowering the amplification gain. This is a mechanistically important distinction: pathogen recognition through Toll-like receptors is untouched, and the pathway is attenuated rather than abolished, which fits the observation that too little TREM-1 signalling is also harmful. The pathway produces its own biomarker. Soluble TREM-1 is shed proportionally to receptor engagement, so its plasma concentration reports on how active the pathway actually is in a given patient at a given moment. That is what makes nangibotide an unusually clean test of precision immunomodulation: the drug targets a pathway whose activation level can be measured directly, rather than inferred from clinical severity. Soluble TREM-1 has moderate diagnostic performance for infection but more consistent prognostic value, particularly when measured serially, and Inotrem has been developing a companion assay with Roche Diagnostics on the Elecsys and cobas platforms since 2017. Preclinically, LR12 tempered deleterious host-pathogen interactions, restored vascular function and improved survival in animal models of septic shock. Vascular dysfunction is the mechanistic bridge to the clinical endpoint — the organ failure measured by the SOFA score in the trials is largely a consequence of microvascular and endothelial injury, and TREM-1 inhibition acts upstream of it. The pathway has also been explored well outside sepsis, including in myocardial infarction, in-stent neoatherosclerosis and osteoarthritis models, which suggests TREM-1 amplification is a general feature of inflammatory tissue injury rather than a sepsis-specific one.

Evidence Snapshot

Research Gaps & Open Questions

What the current literature has not yet settled about Nangibotide:

• 01Does nangibotide improve survival? No trial has been powered for mortality. ASTONISH showed no consistent mortality pattern and a numerically worse result in its low-dose arm; ESSENTIAL reported a 12 percent absolute mortality improvement but stopped early and enrolled 220 patients in a disease whose standard of care changed mid-trial.
• 02What is the correct soluble TREM-1 threshold? The prespecified cutoff of 400 picograms per millilitre failed, and the exploratory finding that 532 picograms per millilitre identifies responders is a post hoc refinement from a negative trial. Until it is tested prospectively it is a hypothesis, and the history of biomarker thresholds derived this way is not encouraging.
• 03Is the dose high enough? High-dose nangibotide outperformed low-dose consistently without either reaching significance, and tolerability was established up to six times the clinical dose in healthy volunteers. Whether the programme has been testing a sub-therapeutic exposure is an open and consequential question.
• 04Will the registration trial run? The FDA agreement on the ACCURATE Phase 3 design was announced in January 2024, and as of late October 2026 no Phase 3 appears in ClinicalTrials.gov. The programme's status is genuinely uncertain in a way that published reviews, which describe the trial as planned, do not convey.
• 05Does timing matter as much as selection? Treatment was started within a fixed window after a clinical trigger, not according to where the patient sat on their own inflammatory trajectory. Serial rather than single soluble TREM-1 measurement has better prognostic performance, which suggests the pathway's activation moves — but no trial has used it to time treatment.
• 06Is there a role outside sepsis? TREM-1 inhibition has shown effects in models of myocardial infarction, in-stent neoatherosclerosis and osteoarthritis, and the COVID-19 trial suggests viral pneumonitis may be a better-defined target than bacterial septic shock. None of these has a clinical programme behind it.
• 07Does attenuating TREM-1 impair pathogen clearance in any subgroup? The trials showed no excess of secondary infection, but they were short, modest in size, and not designed to detect it.

Forms & Administration

Nangibotide is given only as a continuous intravenous infusion, in an intensive care setting, to patients already receiving vasopressors or respiratory support. In ASTONISH the doses were 0.3 and 1.0 milligrams per kilogram per hour, started within 24 hours of vasopressor initiation for septic shock. In ESSENTIAL the dose was 1.0 milligram per kilogram per hour, started within 48 hours of the onset of invasive or non-invasive respiratory support for COVID-19-related ARDS. Treatment typically continues for up to five days. The infusion requirement is a direct consequence of the pharmacokinetics — an effective half-life of roughly 3 minutes leaves no alternative. In the first-in-man study, infusions were preceded by a loading dose of up to 5 milligrams per kilogram over 15 minutes. There is no subcutaneous, oral, inhaled or any other formulation, no approved product, and no supply outside clinical trials. Because the drug is only meaningful in a patient who is already in organ failure, in a unit with continuous haemodynamic monitoring, and selected by a biomarker assay that is not yet commercially deployed, there is no plausible context in which it could be used outside a trial.

Dosing & Protocols

The ranges below reflect protocols commonly discussed in the literature and by clinicians — not a prescription. Actual dosing for any individual should be determined by a qualified healthcare provider who knows the patient.

Nangibotide is an investigational drug that has never been approved by any regulator. It is administered only by continuous intravenous infusion to critically ill patients inside clinical trials, and its intended use depends on a companion biomarker assay that is not commercially deployed. There is no legitimate supply outside a trial, and no context in which a reader could appropriately use it.

Timeline of Effects

Common Questions

Who Nangibotide Is NOT For

Drug & Supplement Interactions

No formal drug interaction studies have been published. The expected profile is clean: nangibotide is a short peptide cleared by enzymatic metabolism in blood with an effective half-life of about three minutes, so cytochrome P450 and transporter-mediated interactions are implausible. In the trials it was given on top of full standard critical care — antibiotics, vasopressors, fluids, mechanical ventilation and renal replacement therapy — without a signal of interaction, though none of these combinations were studied formally. The interactions that matter are immunological and are largely untested. Corticosteroids are the obvious one, since hydrocortisone is standard in refractory septic shock and its broad immunosuppression overlaps with, but is not the same as, TREM-1 pathway attenuation. Whether the two are additive, redundant or counterproductive has not been examined, and trial publications do not report stratified analyses by steroid use. The same question applies to any other immunomodulator a critically ill patient might receive, including interleukin-6 blockade in the COVID-19 setting, which became standard care during the ESSENTIAL enrolment period. One practical interaction deserves naming: renal replacement therapy and extracorporeal circuits are common in this population and can clear or adsorb small peptides. Given a drug with a three-minute half-life delivered by continuous infusion, whether dialysis alters effective exposure is a legitimate question that the published literature does not answer.

Safety Profile

Legal Status

Regulatory status changes over time. Verify current local rules with a qualified professional.

Myths & Misconceptions