IID572

**IID572** is a novel diazabicyclooctane (DBO) class **β-lactamase inhibitor** (BLI) designed to restore the activity of β-lactam antibiotics like piperacillin against resistant Gram-negative bacteria expressing diverse serine β-lactamases, including class A (e.g., KPC-2, CTX-M-15), class C, and OXA-type enzymes. Unlike other DBOs such as avibactam, zidebactam, and nacubactam, it lacks intrinsic antibacterial activity due to no inhibition of penicillin-binding protein 2 (PBP2), potentially simplifying PK/PD predictions and reducing resistance risks from PBP2 mutations. It exhibits potent carbamylation of β-lactamases, broad potentiation of piperacillin against clinical isolates, favorable preclinical pharmacokinetics (low clearance, long half-life), and efficacy in murine thigh infection models against KPC/SHV-expressing *Klebsiella pneumoniae*. Originally discovered by Novartis via late-stage functionalization and scalable synthesis routes.[1][4][7][10][11]