Experimental Antibiotic Shows Promise in Multi-Drug-Resistant Infections

A new drug that can attack several multi-drug resistant pathogens is showing promise.

Investigational antibiotic cefiderocol (S-649266/Shionogi) showed it was effective against Gram-negative pathogens. Those included carbapenem-resistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii, and carbapenem-resistant Enterobacteriaceae (photo), according to results presented Oct. 26 at IDWeek 2016 in New Orleans, LA.

Cefiderocol is a siderophore cephalosporin that uses a “Trojan horse” strategy to getting bacterial cells. Its binds to free iron and is then actively transported through these cells’ outer membrane. It is being studied for use in patients with complicated urinary tract infections and in patients with carbapenem-resistant pathogens at various infection sites.

The results presented at the conference were from in vitro data from 8,765 test strains of those pathogens from patients in North American and Europe in 2014-2015.

Among the key findings, according to the company:

• Cefiderocol showed the lowest MIC₅₀ and MIC₉₀ values of all compounds tested. The growth of 99.6% of all isolates was inhibited at 4 µg/mL of cefiderocol (MIC of <4 µg/mL).
• Cefiderocol was active against many of the Gram-negative pathogens that were not susceptible to other antibiotics (1290 isolates [14.7% of total studied] were non-susceptible to meropenem).
• Cefiderocol had MIC₉₀ values of 1, 1, and 4 μg/mL against meropenem non-susceptible isolates of A. baumannii, P. aeruginosa, and Enterobacteriaceae, respectively; whereas the MIC₉₀ values of both ceftazidime/avibactam and ceftolozane/tazobactam against these pathogens were >32 μg/mL .

Related Coverage:

First Biologic for MDR HIV Seems to Work

Anti-Biofilms Show Promise Against Common Drug-Resistant Bacteria