BAL30072

**BAL30072** is a novel siderophore monosulfactam antibiotic (monocyclic β-lactam class) developed by Basilea Pharmaceutica for treating severe infections caused by multi-drug resistant (MDR) Gram-negative bacteria, including *Pseudomonas aeruginosa*, *Acinetobacter* spp., and *Enterobacteriaceae* producing carbapenemases or metallo-β-lactamases. It exhibits potent bactericidal activity by leveraging a siderophore moiety for active uptake via bacterial iron transporters, combined with high-affinity binding to penicillin-binding proteins (PBPs) such as PBP3, PBP1a, and PBP1b, leading to cell lysis rather than filamentation. The drug shows synergistic or additive effects with carbapenems like meropenem and is stable to most β-lactamases; however, it has demonstrated hepatotoxicity in multiple-dose Phase I studies due to mitochondrial dysfunction, ROS production, and glycolysis inhibition at clinically relevant concentrations. An inhaled formulation is under preclinical development for cystic fibrosis and bronchiectasis lung infections.[1][3][5][7][9][11]