Activity of Eravacycline against Escherichia coli Clinical Isolates Collected from U.S. Veterans in 2011 in Relation to Coresistance Phenotype and Sequence Type 131 Genotype

Activity of Cefiderocol, Ceftazidime-Avibactam, and Eravacycline against Carbapenem-Resistant Escherichia coli Isolates from the United States and International Sites in Relation to Clonal Background, Resistance Genes, Coresistance, and Region

Emerging carbapenem resistance in Escherichia coli, including sequence type 131 (ST131), the leading cause of extraintestinal E. coli infections globally, threatens therapeutic efficacy. Accordingly, we determined broth microdilution MICs for three distinctive newer agents, i.e., cefiderocol (CFDC), ceftazidime-avibactam (CZA), and eravacycline (ERV), plus 11 comparators, against 343 carbapenem-resistant (CR) clinical E. coli isolates, then compared susceptibility results with bacterial characteristics and region. The collection comprised 203 U.S. isolates (2002 to 2017) and 141 isolates from 17 countries in Europe, Latin America, and the Asia-West Pacific region (2003 to 2017). Isolates were characterized for phylogenetic group, resistance-associated sequence types (STs) and subsets thereof, and relevant beta-lactamase-encoding genes. CFDC, CZA, and ERV exhibited the highest percent susceptible (82% to 98%) after tigecycline (TGC) (99%); avibactam improved CZA's activity over that of CAZ (11% susceptible). Percent susceptible varied by phylogroup and ST for CFDC and CZA (greatest in phylogroups B2, D, and F, and in ST131, ST405, and ST648). Susceptibility also varied by resistance genotype, being higher with the Klebsiella pneumoniae carbapenemase (KPC) for CZA, lower with metallo-beta-lactamases for CFDC and CZA, and higher with the beta-lactamase CTX-M for ERV. Percent susceptible also varied by global region for CZA (lower in Asia-Pacific) and by U.S. region for ERV (lower in the South and Southeast). Although resistance to comparators often predicted reduced susceptibility to a primary agent (especially CFDC and CZA), even among comparator-resistant isolates the primary-agent-susceptible fraction usually exceeded 50%. These findings clarify the likely utility of CFDC, CZA, and ERV against CR E. coli in relation to multiple bacterial characteristics and geographical region.

In Vitro Activity of Eravacycline against Gram-Positive Bacteria Isolated in Clinical Laboratories Worldwide from 2013 to 2017

Eravacycline is a novel, fully synthetic fluorocycline antibiotic being developed for the treatment of serious infections, including those caused by resistant Gram-positive pathogens. Here, we evaluated the in vitro activities of eravacycline and comparator antimicrobial agents against a recent global collection of frequently encountered clinical isolates of Gram-positive bacteria. The CLSI broth microdilution method was used to determine in vitro MIC data for isolates of Enterococcus spp. (n = 2,807), Staphylococcus spp. (n = 4,331), and Streptococcus spp. (n = 3,373) isolated primarily from respiratory, intra-abdominal, urinary, and skin specimens by clinical laboratories in 37 countries on three continents from 2013 to 2017. Susceptibilities were interpreted using both CLSI and EUCAST breakpoints. There were no substantive differences (a >1-doubling-dilution increase or decrease) in eravacycline MIC₉₀ values for different species/organism groups over time or by region. Eravacycline showed MIC₅₀ and MIC₉₀ results of 0.06 and 0.12 μg/ml, respectively, when tested against Staphylococcus aureus, regardless of methicillin susceptibility. The MIC₉₀ values of eravacycline for Staphylococcus epidermidis and Staphylococcus haemolyticus were equal (0.5 μg/ml). The eravacycline MIC₉₀s for Enterococcus faecalis and Enterococcus faecium were 0.06 μg/ml and were within 1 doubling dilution regardless of the vancomycin susceptibility profile. Eravacycline exhibited MIC₉₀ results of ≤0.06 μg/ml when tested against Streptococcus pneumoniae and beta-hemolytic and viridans group streptococcal isolates. In this surveillance study, eravacycline demonstrated potent in vitro activity against frequently isolated clinical isolates of Gram-positive bacteria (Enterococcus, Staphylococcus, and Streptococcus spp.), including isolates collected over a 5-year period (2013 to 2017), underscoring its potential benefit in the treatment of infections caused by common Gram-positive pathogens.

In Vitro Activity of Eravacycline against Gram-Negative Bacilli Isolated in Clinical Laboratories Worldwide from 2013 to 2017

Eravacycline is a novel, fully synthetic fluorocycline antibiotic developed for the treatment of serious infections, including those caused by multidrug-resistant (MDR) pathogens. Here, we evaluated the in vitro activities of eravacycline and comparator antimicrobial agents against a global collection of frequently encountered clinical isolates of Gram-negative bacilli. The CLSI broth microdilution method was used to determine MIC data for isolates of Enterobacterales (n = 13,983), Acinetobacter baumannii (n = 2,097), Pseudomonas aeruginosa (n = 1,647), and Stenotrophomonas maltophilia (n = 1,210) isolated primarily from respiratory, intra-abdominal, and urinary specimens by clinical laboratories in 36 countries from 2013 to 2017. Susceptibilities were interpreted using both CLSI and EUCAST breakpoints. Multidrug-resistant (MDR) isolates were defined by resistance to agents from ≥3 different antimicrobial classes. The MIC₉₀s ranged from 0.25 to 1 μg/ml for Enterobacteriaceae and were 1 μg/ml for A. baumannii and 2 μg/ml for S. maltophilia, Proteus mirabilis, and Serratia marcescens Eravacycline's potency was up to 4-fold greater than that of tigecycline against genera/species of Enterobacterales, A. baumannii, and S. maltophilia The MIC₉₀s for five of six individual genera/species of Enterobacterales and A. baumannii were within 2-fold of the MIC₉₀s for their respective subsets of MDR isolates, while the MDR subpopulation of Klebsiella spp. demonstrated 4-fold higher MIC₉₀s. Eravacycline demonstrated potent in vitro activity against the majority of clinical isolates of Gram-negative bacilli, including MDR isolates, collected over a 5-year period. This study further underscores the potential benefit of eravacycline in the treatment of infections caused by MDR Gram-negative pathogens.

Evaluation of Eravacycline: A Novel Fluorocycline

Eravacycline (ERV), formerly known as TP-434, is a novel tetracycline (TET) antibiotic that exhibits in vitro activity against various gram-positive, gram-negative aerobic and anaerobic pathogens, including those exhibiting TET-specific acquired resistance mechanisms. Similar to other TETs, it inhibits protein synthesis through binding to the 30S ribosomal subunit. Eravacycline was approved by the United States Food and Drug Administration (FDA) in August 2018 for the treatment of complicated intraabdominal infections (cIAIs) in adults following the Investigating Gram-Negative Infections Treated with Eravacycline (IGNITE)1 and IGNITE4 phase III trials. In these two, double-blind, multicenter clinical trials, ERV was proven noninferior in terms of clinical response in comparison to ertapenem and meropenem, respectively. Eravacycline was well tolerated with nausea, vomiting, and infusion site reactions being the most commonly reported adverse reactions. Clinicians now have ERV as a novel therapeutic option for the treatment of adults with intraabdominal infections, allergies to β-lactam agents, Clostridioides difficile-associated diarrhea, or if tolerability to other agents is a concern.

Eravacycline: The Tetracyclines Strike Back

Objective: To review the pharmacology, pharmacokinetics, efficacy, safety, and place in therapy of eravacycline, a novel fluorocycline antibiotic from the tetracycline family. Data Sources: A PubMed search was conducted for data between 1946 and March 2019 using MeSH terms eravacycline and TP-434. An internet search was conducted for unpublished clinical research. Study Selection and Data Extraction: The literature search was limited to English-language studies that described clinical efficacy, safety, and pharmacokinetics in humans and animals. Abstracts featuring prepublished data were also evaluated for inclusion. Data Synthesis: Eravacycline has in vitro activity against multidrug-resistant organisms, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, extended-spectrum β-lactamase-producing and carbapenem-resistant Enterobacteriaceae, and Acinetobacter. It was approved for the treatment of complicated intra-abdominal infections (cIAIs) in adults following favorable results of 2 phase III trials, IGNITE 1 and IGNITE 4, compared with ertapenem and meropenem, respectively. The most common adverse drug events associated with eravacycline were infusion site reactions (7.7%), nausea (6.5%), vomiting (3.7%), and diarrhea (2.3%). Relevance to Patient Care and Clinical Practice: Eravacycline will likely be most useful for resistant infections when lack of tolerability, resistant phenotypes, or allergies prevent the use of β-lactams. Conclusions: Eravacycline is a new tetracycline antibiotic with a broad spectrum of activity that has demonstrated efficacy in the treatment of cIAIs. Although it has activity against multidrug-resistant organisms, data are limited for other indications.

Randomized, Double-Blind, Placebo-Controlled Studies of the Safety and Pharmacokinetics of Single and Multiple Ascending Doses of Eravacycline

Eravacycline is a novel, fully synthetic fluorocycline antibiotic with in vitro activity against aerobic and anaerobic Gram-positive and Gram-negative pathogens, including multidrug-resistant (MDR) bacteria. The pharmacokinetics (PK), urinary excretion, and safety/tolerability of intravenous (i.v.) eravacycline were evaluated in single- and multiple-ascending-dose studies.

Eravacycline is a novel, fully synthetic fluorocycline antibiotic with in vitro activity against aerobic and anaerobic Gram-positive and Gram-negative pathogens, including multidrug-resistant (MDR) bacteria. The pharmacokinetics (PK), urinary excretion, and safety/tolerability of intravenous (i.v.) eravacycline were evaluated in single- and multiple-ascending-dose studies. Healthy subjects received single i.v. doses of 0.1 to 3 mg/kg of body weight or 10 days of treatment with 0.5 or 1.5 mg/kg every 24 h (q24h) over 30 min, 1.5 mg/kg q24h over 60 min, or 1 mg/kg q12h over 60 min. After single doses, total exposure (the area under the plasma concentration-time curve [AUC]) and the maximum plasma concentrations (C_max) of eravacycline increased in an approximately dose-proportional manner. After multiple doses, steady state was achieved within 5 to 7 days. Accumulation ranged from approximately 7% to 38% with the q24h dosing regimens and was 45% with 1 mg/kg q12h. Eravacycline was generally well tolerated, with dose-related nausea, infusion site effects, and superficial phlebitis that were mild or moderate occurring. These results provide support for the 1-mg/kg q12h regimen used in clinical studies of eravacycline.

In vitro activity of eravacycline against 2213 Gram-negative and 2424 Gram-positive bacterial pathogens isolated in Canadian hospital laboratories: CANWARD surveillance study 2014-2015

Gram-negative (n=2213) and Gram-positive (n=2424) pathogens isolated from patients in 13 Canadian hospitals in 2014 and 2015 were tested for in vitro susceptibility to eravacycline and comparators using the Clinical and Laboratory Standards Institute broth microdilution method. The concentration of eravacycline inhibiting 90% of isolates (MIC₉₀) ranged from 0.5 to 2μg/mL for 9 species of Enterobacteriaceae tested (n=2067). Eravacycline activity was largely unaffected by extended-spectrum β-lactamase phenotypes in Escherichia coli (n=141) and Klebsiella pneumoniae (n=21). Eravacycline was active against Acinetobacter baumannii (n=28; MIC₉₀, 0.5μg/mL) and Stenotrophomonas maltophilia (n=118; MIC₉₀, 4μg/mL). Eravacycline MIC₉₀ for staphylococci (n=1653), enterococci (n=289), and streptococci (n=482) ranged from 0.12 to 0.25, 0.06 to 0.12, and 0.015 to 0.06μg/mL, respectively. Eravacycline's potency was equivalent to or 2- to 4-fold greater than tigecycline against Enterobacteriaceae and Gram-positive cocci tested. Eravacycline demonstrates promising activity against recent clinical Gram-negative and Gram-positive bacteria, including multidrug-resistant pathogens.

In vitro susceptibility of β-lactamase-producing carbapenem-resistant Enterobacteriaceae (CRE) to eravacycline

Eravacycline is a novel, fully synthetic fluorocycline antibiotic of the tetracycline class being developed for the treatment of complicated urinary tract infections and complicated intra-abdominal infections. Eravacycline has activity against many key Gram-negative pathogens, including Enterobacteriaceae resistant to carbapenems, cephalosporins, fluoroquinolones and β-lactam/β-lactamase inhibitor combinations, including strains that are multidrug-resistant. Carbapenem-resistant Enterobacteriaceae (CRE) isolates from 2010 to 2013 (n=110) were characterized for carbapenemase genes by PCR and sequencing. MICs for eravacycline, tetracycline, tigecycline, amikacin, imipenem, ceftazidime, cefotaxime and levofloxacin were determined in broth microdilution assays. All isolates produced at least one carbapenemase, most frequently KPC-3. Nine isolates produced both a KPC serine carbapenemase and a metallo-β-lactamase, NDM-1 (n=1) or VIM-1 (n=8). The 110 isolates were highly resistant to all the β-lactams tested and to levofloxacin, and had MIC50/MIC90 values in the intermediate range for tetracycline and amikacin. MIC50/MIC90 values for eravacycline were 1/2 μg ml(-1) compared with 2/2 μg ml(-1) for tigecycline. Eravacycline MICs were often twofold lower than for tigecycline, with 64% of the eravacycline MICs <2 μg ml(-1) as compared with <4% of tigecycline MICs. Overall, eravacycline demonstrated the lowest cumulative MICs against this panel of recent CRE and may have the potential to treat infections caused by CRE.