PP1131

**PP1131** is an investigational topical bacteriophage product developed by Pherecydes Pharma for *Pseudomonas aeruginosa* burn-wound infections. It is a defined cocktail of 12 natural lytic anti-*P. aeruginosa* bacteriophages intended to infect, replicate within, and lyse susceptible bacterial cells. In the randomized Phase 1/2 PhagoBurn trial, PP1131 was administered daily to burn wounds for 7 days, but the trial was stopped because the product delivered at a substantially lower-than-intended phage titre and reduced bacterial burden more slowly than silver sulfadiazine standard care. ([iris.unil.ch](https://iris.unil.ch/entities/publication/acdce1bd-7105-4afa-b3f5-36ff478e9a9c))