Murepavadin
Antimicrobial 'protegrin' peptidomimetic
Also POL7080, POL-7080, Murepavadin inhaled
- Evidence
- CAnimal and cell studies
- FDA status
- In clinical trialsas of 2026-10-27
- Route
- Intravenous
- Studies cited
- 2 human0 animal or cell
It is an antibiotic meant for a hard-to-treat hospital germ. Two big trials were stopped in 2019 because it hurt patients' kidneys.
Sold for
Murepavadin is discussed as the first of a new antibiotic class that could kill drug-resistant Pseudomonas aeruginosa, the hospital pathogen behind many ventilator pneumonias.
Studies say
Phase 1 and small phase 2 data showed it reaches the blood and clears Pseudomonas in small uncontrolled series, but the phase 3 trials were stopped for kidney injury, leaving grade C evidence.
Why grade C. The cited human data are a randomized, placebo-controlled phase 1 pharmacokinetic and safety study in healthy men (10 single-dose cohorts of six plus three multiple-dose cohorts) and a small phase 2 study in ventilator-associated pneumonia summarized in a review. The two randomized phase 3 trials were halted early for kidney toxicity and never published as efficacy studies. Controlled human efficacy data therefore do not exist in the literature, so the grade is C despite a large development program. 1234
FDA. Not approved by the FDA for any use. Murepavadin is an investigational antibiotic; Polyphor stopped its two phase 3 trials of the intravenous form in 2019 after excess kidney injury. An inhaled formulation for cystic fibrosis lung infection was later developed by Spexis with Cystic Fibrosis Foundation funding, but the foundation now lists that program as discontinued, with no active development.
Written from 4 cited sources. Fact-checked 2026-10-27: 16 claims checked, 9 corrected. Last refreshed 2026-10-27. Not physician reviewed.
What this means for you
- What people take it for
- Treating drug-resistant lung infections in hospital
- Can a US doctor prescribe it?
- Not yet; it is still in trials.
- Properly tested in people?
- Not properly: animal or lab studies, or small uncontrolled human reports. The two big trials were stopped early.
Evidence checklist
- Randomised controlled trial Phase 3 RCTs stopped; results unpublishedno
- Human study over 100 people Cited human studies are smallno
- More than one research group Article does not sayno information
- Clinical outcomes, not surrogate markers No efficacy outcome from phase 3no
- Human safety data beyond case reports Kidney injury in over half in phase 3yes
Drawn from the cited studies below. A dash means the sources give no information.
What it is
Murepavadin (POL7080) is a synthetic 14-amino-acid cyclic peptidomimetic modeled on protegrin I, an antimicrobial peptide from pig white blood cells. Polyphor in Switzerland designed it to keep protegrin's killing power while making it specific for one bacterium, Pseudomonas aeruginosa. It belongs to a new class called outer membrane protein targeting antibiotics. 1
It was developed as an intravenous drug for hospital- and ventilator-acquired pneumonia caused by Pseudomonas. Two phase 3 trials (PRISM-MDR and PRISM-UDR) started in 2018; enrollment was paused in May 2019 and the trials were closed in July 2019 after acute kidney injury occurred in about 56 percent of treated patients, against an expected 25 to 40 percent in this very sick population. Polyphor said the decision did not affect its inhaled murepavadin program. 34
How it works
Murepavadin binds LptD, a protein in the outer membrane of Pseudomonas that inserts lipopolysaccharide, the lipid-sugar molecule that forms the outer leaflet of the membrane. Blocking LptD stops outer membrane assembly and the bacterium dies. Because LptD differs between bacterial species, murepavadin is active against Pseudomonas and not much else, which spares the patient's other bacteria but also means it cannot be used alone when the pathogen is unknown. It retains activity against strains resistant to carbapenems and colistin. 12
What human research shows
A double-blind, randomized, placebo-controlled phase 1 study in healthy men tested single and repeated intravenous doses. Murepavadin had a half-life of about 2.5 to 5.3 hours, its exposure rose in proportion to dose, and adverse events were transient and mostly mild, with no dose-limiting toxicity. A small phase 2 study characterized its pharmacokinetics in patients with Pseudomonas ventilator-associated pneumonia; Polyphor described the phase 2 results as promising but full efficacy data are not in the cited sources. 123
The phase 3 trials would have been the controlled test. They were stopped early; Polyphor reported 28-day mortality of 30.0 percent on murepavadin versus 37.5 percent on comparator at the time of closure, numbers too small to interpret and never peer-reviewed. 4
| Study | Model | Finding |
|---|---|---|
| Murepavadin program review (Martin-Loeches 2018) | Review of in vitro, animal and clinical pharmacology data, including pharmacokinetics in VAP patients | Potent activity against carbapenemase-producing and colistin-resistant Pseudomonas, efficacy in animal infection models, and well-characterized pharmacokinetics. 1 |
| Phase 1 pharmacokinetics and safety (Dale 2018) | Humans, healthy men, randomized double-blind placebo-controlled, single and multiple ascending doses | Dose-proportional pharmacokinetics, half-life of 2.5 to 5.3 hours, mostly mild transient adverse events and no dose-limiting toxicity. 2 |
| PRISM-MDR closure (Polyphor 2019) | Humans, randomized phase 3 in Pseudomonas hospital pneumonia, stopped early | Acute kidney injury in 56% on murepavadin versus an expected 25 to 40%; 28-day mortality 30.0% versus 37.5% on comparator. 4 |
Safety
Acute kidney injury is the established problem: more than half of treated patients in PRISM-MDR developed it, a rate well above the control arm and above what the disease alone produces. The drug is cleared by the kidneys and the mechanism of the toxicity, possibly shared with colistin and other cationic peptides, has not been explained. Phase 1 data showed no other major signal, but exposure was short and in healthy people, and whether the inhaled formulation avoids the kidney problem is unanswered. 234
Questions for your clinician
- Is the inhaled form free of the kidney injury seen with the injection?
- What treatments for Pseudomonas currently have trial support?
- Is there a trial I could join?
Questions people ask
Is murepavadin FDA-approved?
No. Its intravenous phase 3 trials were closed in 2019 for kidney toxicity, and no murepavadin product has been approved. 34
Citations
- Martin-Loeches 2018, Expert Rev Anti Infect Ther: Murepavadin, a new antibiotic class in the pipeline doi.org
- Wach 2018, Antimicrob Agents Chemother: pharmacokinetics and safety of intravenous murepavadin in healthy adults, single and multiple ascending doses doi.org
- Polyphor press release, May 2019: enrollment halted in the phase 3 PRISM trials of murepavadin biospace.com
- Polyphor press release, July 2019: phase 3 PRISM studies of intravenous murepavadin closed biospace.com