LSALT peptide

Mechanism of action

Dipeptidase-1 (DPEP1) sits on the lining of blood vessels in the lung, liver and kidney, where it works as a physical docking point for neutrophils rather than through the enzyme activity its name describes; the peptide binds it and blocks the docking, leaving the enzyme alone (PMIDs 31442408, 35108057). In mice, pretreatment before the kidney lost and regained its blood supply cut neutrophil adhesion in the peritubular capillaries and the recruitment of inflammatory monocytes, and left less kidney injury; blocking CD44 added to the effect and blocking ICAM-1 did not (PMID 35108057). In the COVID-19 trial the treated group's blood CXCL10, a signal that draws immune cells into tissue, fell further from baseline than on placebo (PMID 38490660).

Primary uses

• Investigational: preventing acute kidney injury after on-pump cardiac surgery (phase 2, recruiting)
• Investigational: preventing respiratory failure and acute kidney injury in hospitalised COVID-19 (phase 2a, completed, no clear benefit)

Typical dosing

Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.

Regulatory status

Not approved anywhere: Drugs@FDA and the openFDA label endpoint hold no record for LSALT peptide or Metablok, and the EMA medicines list holds none (searched November 4, 2026). Arch Biopartners has registered three trials of its own: a phase 1 single and multiple ascending dose study in 52 healthy adults in Australia (NCT03772678, completed March 2020, results posted), the phase 2a COVID-19 trial in 61 patients (NCT04402957, completed, published as PMID 38490660) and a 240-patient phase 2 trial of kidney protection in on-pump cardiac surgery (NCT05879432, recruiting, primary completion estimated March 2027). The Canadian CATCO platform trial lists it among the drugs it may test (NCT04330690, phase 3, last known status active and not recruiting). ChEMBL records a highest clinical phase of 3 (CHEMBL5314991); the only phase 3 record that names the peptide is that platform trial, and its own sponsor's trials are phase 1 and phase 2.

Status as of this entry's last review, November 4, 2026. Approvals, compounding rules and sport rules change; the regulatory tracker is checked more often.

What the studies show

Two indexed papers study this peptide itself: one trial in people and one in mice. Its four registered trials are listed after them. Papers about the receptor DPEP1, and nanoparticles that carry the peptide as a targeting tag, are different subjects and are not cards here.

References

1. [clinical-trial] Somayaji R, et al. "Multicentre, randomised, double-blind, placebo-controlled, proof of concept study of LSALT peptide as prevention of acute respiratory distress syndrome and acute kidney injury in patients infected with SARS-CoV-2 (COVID-19)." BMJ Open, 2024;14(3):e076142. PMID: 38490660.
2. [pubmed] Lau A, et al. "Dipeptidase-1 governs renal inflammation during ischemia reperfusion injury." Sci Adv, 2022;8(5):eabm0142. PMID: 35108057.
3. [pubmed] Choudhury SR, et al. "Dipeptidase-1 Is an Adhesion Receptor for Neutrophil Recruitment in Lungs and Liver." Cell, 2019;178(5):1205-1221.e17. PMID: 31442408.
4. [clinicaltrials] ClinicalTrials.gov NCT03772678: "A Phase I Double-blind, Placebo-controlled, Randomized, Single and Multiple Ascending Dose Finding Study to Evaluate the Safety and Pharmacokinetic Profile of LSALT Peptide in Healthy Participants" Arch Biopartners Inc. 52 participants, one site in Melbourne, Australia, June 2019 to March 2020, completed with results posted: single intravenous doses of 0.01, 0.1, 0.3, 0.5, 1.0, 2.5 and 5.0 mg and 1.0, 2.5 or 5.0 mg once daily for three days, each infused over two hours; no severe, life-threatening or serious treatment-emergent adverse event in any group; mean terminal half-life 0.41 hours (SD 0.147) after a single 5 mg dose and 0.21 hours (SD 0.075) in the 5 mg daily cohort. Registry record read November 4, 2026.
5. [clinicaltrials] ClinicalTrials.gov NCT04402957: the phase 2a COVID-19 trial of LSALT peptide against placebo, Arch Biopartners Inc., 61 participants at seven sites in Canada, Turkey and the United States, October 2020 to June 2022, completed; 5 mg infused intravenously over two hours once daily for up to 14 days; published in BMJ Open in 2024 (the trial paper is cited above). Registry record read November 4, 2026.
6. [clinicaltrials] ClinicalTrials.gov NCT05879432: "Phase 2 Global, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study of LSALT Peptide for the Prevention or Attenuation of Acute Kidney Injury (AKI) in Patients Undergoing On-Pump Cardiac Surgery" Arch Biopartners Inc. 240 patients planned at nine sites in Canada and Turkey, recruiting since March 2024, primary completion estimated March 2027; 10 mg or placebo infused over one hour twice daily for five days, the first dose at least an hour before anaesthesia; primary endpoint acute kidney injury by KDIGO criteria within seven days of surgery. Registry record read November 4, 2026.
7. [clinicaltrials] ClinicalTrials.gov NCT04330690 (CATCO), the Canadian arm of the World Health Organization's SOLIDARITY platform trial of COVID-19 treatments, Sunnybrook Health Sciences Centre: LSALT peptide is one of its listed investigational drugs, 5 mg as a two-hour intravenous infusion once daily for up to 14 consecutive days. Phase 3, last known status active and not recruiting, status last verified January 2023; no results posted. Registry record read November 4, 2026.
8. [other] ChEMBL molecule CHEMBL5314991 (LSALT PEPTIDE), read November 4, 2026: highest clinical phase recorded 3. No sequence, formula or mass is given in the record. https://www.ebi.ac.uk/chembl/compound_report_card/CHEMBL5314991/
9. [other] US FDA, Drugs@FDA and the drug label endpoint (openFDA), searched November 4, 2026: no application and no label record for LSALT peptide or Metablok.

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