In short
OMN6 is an investigational antimicrobial peptide being developed for infections caused by multidrug-resistant Gram-negative bacteria. It is currently in Phase 2 clinical testing for hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP) caused by Acinetobacter baumannii complex. One registered trial is evaluating the safety, tolerability, and pharmacokinetics of OMN6 in 36 participants.
OMN6 is an investigational bioengineered antimicrobial peptide. It is a 40-amino acid cyclic peptide based on Cecropin A, developed to target multidrug-resistant Gram-negative bacteria. The substance is also known as OMN-6 or OMN 6. It is not yet an authorised medicine; it is still under clinical investigation.
Key points
- OMN6 is a bioengineered cyclic peptide designed to kill multidrug-resistant Gram-negative bacteria.
- The current trial is in Phase 2 and is authorised but not yet recruiting.
- The study focuses on hospital-acquired and ventilator-associated bacterial pneumonia caused by Acinetobacter baumannii complex.
- 36 participants are planned to be enrolled in this single-day treatment study.
- The trial compares OMN6 given intravenously against a saline placebo.
- Main outcomes include safety, tolerability, and how the body processes the drug (pharmacokinetics).
What is OMN6?
OMN6 is a novel cyclic peptide engineered from Cecropin A, a naturally occurring antimicrobial peptide. It belongs to the class of antibacterials and acts as a bacterial outer membrane protein inhibitor. The substance is a chemically engineered peptide designed to combat bacteria that have become resistant to many existing antibiotics. OMN6 is classified as a new molecular entity and has reached Phase 2 clinical development for Gram-negative infections.
How does OMN6 work?
OMN6 works by targeting the bacterial membrane, unlike many conventional antibiotics that bind to a specific enzyme or bacterial site inside the cell. This membrane-targeting mechanism is bactericidal, meaning it kills bacteria rather than merely stopping their growth. Because OMN6 acts on the membrane itself, it is effective against Acinetobacter baumannii laboratory strains and clinical isolates regardless of the bacteria's genotype or resistance phenotype. This makes the development of resistance through mutation much less likely compared to small-molecule antibiotics. OMN6 also shows increased stability and reduced proteolytic degradation, meaning it is not easily broken down by enzymes.
Which conditions is OMN6 used or studied for?
- Hospital-acquired bacterial pneumonia (HABP) — a lung infection that develops during a hospital stay, in this case caused by Acinetobacter baumannii complex.
- Ventilator-associated bacterial pneumonia (VABP) — a lung infection that occurs in people who are on a breathing machine (ventilator), also caused by Acinetobacter baumannii complex.
- Gram-negative infections — OMN6 has been developed for infections caused by Gram-negative bacteria, which are among the most difficult to treat due to antibiotic resistance.
How is OMN6 given?
In the registered clinical trial, OMN6 is given by intravenous administration at a dose of 450 mg. The pharmaceutical form used in the trial is a solution for intravenous use. The comparison arm receives saline (a saltwater solution) by intravenous infusion.
What do the clinical trials show?
One clinical trial of OMN6 is registered in the EU Clinical Trials Information System and on ClinicalTrials.gov. This Phase 2 study is authorised but not yet recruiting participants. It plans to enrol 36 participants with hospital-acquired or ventilator-associated bacterial pneumonia caused by Acinetobacter baumannii complex.
The trial is designed to evaluate the safety and tolerability of single-day, dose-escalating OMN6 compared to placebo. It will also measure the pharmacokinetic (PK) profile of OMN6 — that is, how the drug is absorbed, distributed, broken down, and eliminated by the body.
What is being measured in the trial?
The primary outcomes include the incidence of treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs), assessed by frequency, severity, relatedness to treatment, and outcome. The study also measures changes in clinical laboratory findings, vital signs, and electrocardiograms (ECGs) from baseline, as well as 28-day all-cause mortality (ACM). Pharmacokinetic parameters of OMN6 are also a primary outcome.
Who can take part in the trial?
The trial enrols participants who have hospital-acquired bacterial pneumonia or ventilator-associated bacterial pneumonia associated with Acinetobacter baumannii complex. These are patients who developed pneumonia during a hospital stay or while on a ventilator.
What side effects are known?
Preclinical studies have shown that OMN6 has a full safety margin on erythrocytes (red blood cells) and HEK293T cells, a commonly used human cell line in laboratory testing. This suggests that OMN6 is non-toxic to human cells at the concentrations tested. The current Phase 2 trial is specifically designed to assess the safety and tolerability of OMN6 in humans, including the frequency and severity of any treatment-emergent adverse events and serious adverse events. Detailed information on side effects in humans is not yet available, as the trial has not reported results.