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 lab-made cyclic peptide of 14 amino acids. It is a peptidomimetic, modeled on protegrin I. That is an antimicrobial peptide from pig white blood cells. Polyphor in Switzerland designed it to keep protegrin's killing power. It was also meant to hit one germ only, Pseudomonas aeruginosa. It belongs to a new class called outer membrane protein targeting antibiotics. 1
It was developed as an intravenous drug for pneumonia caused by Pseudomonas. This covers pneumonia acquired in hospital or on a ventilator. Two phase 3 trials (PRISM-MDR and PRISM-UDR) started in 2018. Enrollment was paused in May 2019. The trials were closed in July 2019. About 56 percent of treated patients had acute kidney injury. The expected rate in this very sick group was 25 to 40 percent. Polyphor said the decision did not affect its inhaled murepavadin program. 34
How it works
Murepavadin binds LptD. This is a protein in the outer membrane of Pseudomonas. It inserts lipopolysaccharide, the fat-sugar molecule that forms the outer layer of the membrane. Blocking LptD stops the outer membrane from being built. The bacterium dies. LptD differs between bacterial species. So murepavadin is active against Pseudomonas and not much else. That spares the patient's other bacteria. But it also means doctors cannot use it alone when the germ is unknown. It stays active against strains resistant to carbapenems and colistin. 12
What human research shows
A phase 1 study in healthy men was double-blind, randomized and placebo-controlled. It tested single and repeated intravenous doses. Murepavadin had a half-life of about 2.5 to 5.3 hours. Exposure rose in proportion to dose. Adverse events were short-lived and mostly mild. No dose-limiting toxicity appeared. A small phase 2 study tracked how the drug moves through the body. The patients had Pseudomonas ventilator-associated pneumonia. Polyphor called the phase 2 results promising. But the cited sources do not include full data on whether it works. 123
The phase 3 trials would have been the controlled test. They were stopped early. At closure, Polyphor reported 28-day mortality. It was 30.0 percent on murepavadin and 37.5 percent on the comparator. These numbers are too small to interpret. No journal ever reviewed them. 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. That rate was well above the control arm. It was also above what the disease alone produces. The kidneys clear the drug. No one has explained the cause of the toxicity. It may be shared with colistin and other cationic peptides. Phase 1 data showed no other major signal. But exposure was short and in healthy people. And it is not yet known whether the inhaled form avoids the kidney problem. 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. 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