High-priority and challenging pathogens are highly susceptible to Fetroja in vitro1

In this study, susceptibility of >38,000 Gram-negative clinical isolates from multiple countries (2013-2018) was tested against Fetroja

In vitro activity does not necessarily correlate with clinical efficacy.

Enterobacteralesa Overall (n=25,995) 100% Enterobacteralesa carbapenem-non-susceptible (n=814) 97% P aeruginosaa Overall (n=6213) 98% P aeruginosaa carbapenem-non-susceptible (n=1416) 95% A baumannii complexa Overall (n=4185) 90% A baumannii complexa carbapenem-non-susceptible (n=2274) 85% S maltophiliab (inherently carbapenem-resistant)2,3 Overall (n=1565) 100%

In a phylogenetic reclassification performed in 2016, the nomenclature of Enterobacterales was proposed, which includes formerly established Enterobacteriaceae family and other genera such as Proteus spp, Providencia spp, Photorhabdus spp, and Serratia spp.4

Fetroja has no clinically relevant in vitro activity against most Gram-positive bacteria or anaerobic bacteria5

a
FDA breakpoints used for Enterobacterales MIC ≤4 μg/mL, P aeruginosa MIC ≤1 μg/mL, and A baumannii complex MIC ≤1 μg/mL.
b
CLSI investigational breakpoint used for S maltophilia MIC ≤4 μg/mL.

In vitro susceptibility study design1

Clinical isolates of Gram-negative bacteria were collected from 4 global surveillance studies (SIDERO-WT-2014, SIDERO-WT-2015, SIDERO-WT-2016, and SIDERO-WT-2018) that included Enterobacterales* and non-fermenter strains. The global surveillance study (Proteeae†) collected clinical isolates from 2013-2016, and were tested centrally (IHMA Inc., Schaumburg, IL, USA). Fetroja MICs were determined by microbroth dilution using iron-depleted cation-adjusted Mueller-Hinton broth (ID-CAMHB) as approved by the Clinical and Laboratory Standards Institute (CLSI) subcommittee on antimicrobial susceptibility testing in January 2016.

FDA breakpoints were used for Enterobacterales MIC ≤4 μg/mL, P aeruginosa MIC ≤1 μg/mL, and A baumannii complex‡ MIC ≤1 μg/mL, whereas CLSI investigational breakpoint was used for S maltophilia MIC ≤4 μg/mL. Carbapenem-non-susceptible strain was defined as meropenem MIC ≥2 μg/mL for Enterobacterales strains (including Proteeae) and MIC ≥4 μg/mL for P aeruginosa and A baumannii complex.

*
E coli, K pneumoniae, other Klebsiella spp, Enterobacter spp, Serratia spp, and Citrobacter spp.
†
M morganii, P mirabilis, P vulgaris, and P rettgeri.
‡
A baumannii complex consists of A baumannii, A calcoaceticus, A dijkshoorniae, A nosocomialis, A pittii, and A seifertii.

Even carbapenem-non-susceptible pathogens remain susceptible to Fetroja in vitro1