Murepavadin

Polyphor, later Spexis, developed murepavadin as a cyclized protegrin-derived peptidomimetic against Pseudomonas aeruginosa, including resistant strains associated with hospital and lung infections. IV development targeted hospital- and ventilator-associated pneumonia; an inhaled formulation was explored later. It remains investigational.

The species-specific target is LptD, the outer-membrane protein required to transport and assemble lipopolysaccharide. Inhibiting it disrupts membrane construction through a non-lytic mechanism. Laboratory work found activity even against multidrug- and colistin-resistant strains, but laboratory susceptibility does not establish patient benefit or safety.

Supporting references: LptD.

An indexed Phase 1 study characterized IV pharmacokinetics and initial safety in healthy volunteers. The subsequent Phase 3 PRISM pneumonia program suspended enrollment and closed in 2019 after more acute kidney injury than expected in the murepavadin group. This is the pivotal clinical story, rather than a positive confirmatory efficacy finding. Reviews discuss its novel antibacterial class, but that profile does not override the kidney signal.

Supporting references: study.

No FDA approval is established. The IV Phase 3 program ended, the developer was later restructured and the reported account identifies no active development. Earlier inhaled exploration should not be presented as a currently approved or clinically established alternative.