Metallo-β-lactamase-IN-9 (Compound 23) is a broad-spectrum inhibitor of metallo-beta-lactamases (MBL), with inhibition constants (IC50) of 35 nM for NDM-1, 269 nM for VIM-1, and 369 nM for IMP-1 [1].

Metallo-β-lactamase-IN-9 (Compound 23), co-administered with Imipenem at doses of 10 and 50 mg/kg and injected subcutaneously three times daily, effectively reduced bacterial load in the spleens and kidneys of mice in a Klebsiella pneumoniae MB9249 infection model [1]. Pharmacokinetic analysis in mice showed that a single intravenous dose (1 mg/kg) produced an AUC of 27.08 μM·h, MRT of 5.2 hours, Vdss of 2.97 L/kg, and Cl of 9.33 mL/min/kg. Subcutaneous administration resulted in an AUC of 27.42 μM·h at 10 mg/kg and 111.28 μM·h at 50 mg/kg, with Cmax values of 13.4 μM and 69.1 μM and Tmax of 0.83 and 0.5 hours, respectively. Formulations included Compound 23 at 1.0 mg/mL in 20% DMSO/60% PEG400/20% water for intravenous delivery (5 mL/kg) and at 1.0 mg/mL or 5.0 mg/mL in 30% captisol for subcutaneous injection (10 mL/kg) [1].