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Updated: Jul 6, 2026

Quadruple-Checkerboard: A Modification of the Three-Dimensional Checkerboard for Studying Drug Combinations
Published on: July 24, 2021
New antibacterial agents for treating infections caused by multi-drug resistant Gram-negative bacteria
1University of Leeds, Antimicrobial Research Centre & Institute of Molecular and Cellular Biology, LS2 9JT, UK. a.j.oneill@leeds.ac.uk
Background:
Infections caused by multi-drug resistant (MDR) Gram-negative bacteria represent an ever-growing area of unmet medical need. To address this need, it is imperative that novel classes of antibiotics demonstrating activity against bacterial strains resistant to established antibiotics are introduced into the clinic.
Objectives:
To examine the current status of the Gram-negative antibacterial pipeline, ranging from the more advanced preclinical candidates to drugs recently launched, and look to the future of anti-Gram-negative drug development.
Methods:
Information was compiled from scientific and patent literature, conference proceedings and company publications/websites.
Results/Conclusions:
None of the antibacterial agents currently in clinical trials that encompass Gram-negative bacteria in their spectrum of activity possess sufficiently novel modes of action to circumvent extant antibiotic resistance mechanisms. Furthermore, although some interesting anti-Gram-negative drug candidates are nearing the beginning of clinical trials, they are limited in number and, even in the best-case scenario, many years away from the clinic.
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