Carbapenem-Resistant Acinetobacter spp Infection in Critically Ill Patients With Limited Treatment Options: A Descriptive Study of Cefiderocol Therapy During the COVID-19 Pandemic

Effectiveness and Safety of Cefiderocol in Clinical Practice for Treatment of Patients with Gram-Negative Bacterial Infections: US Interim Results of the PROVE Study

Purpose

The international PROVE retrospective chart-review study aims to assess the real-world effectiveness and safety of cefiderocol for treatment of patients with carbapenem-resistant Gram-negative infections.

Patients and Methods

US centers selected hospitalized patients receiving their first cefiderocol treatment for ≥72 hours for a Gram-negative bacterial infection (November 2020-March 2023). Patient demographics, clinical characteristics, hospitalization, course of infection, antibiotic use, clinical cure (excluding patients with a relapse/reinfection), clinical response at the end of treatment, microbiology, in-hospital all-cause mortality (IH-ACM) at Day 30, and safety were analyzed using descriptive statistics.

Results

This interim analysis included 244 patients. The most frequent infection sites were respiratory tract (55.7%), skin and skin structure (16.8%), and blood (9.8%). The median duration of cefiderocol use was 12 days (interquartile range 8-18.5). Clinical cure was reported for 64.8% (158/244) of patients, clinical response for 74.2% (181/244), and 9.4% (23/244) had relapse/reinfection; 30-day IH-ACM was 18.4% (45/244). Of 82 patients with monomicrobial Pseudomonas aeruginosa infections, 64.6% (n = 53) and 74.4% (n = 61) had clinical cure and clinical response, respectively, and 30-day IH-ACM was 25.6%. Among 43 patients with monomicrobial Acinetobacter baumannii infections, 60.5% (n = 26) and 74.4% (n = 32) had clinical cure and clinical response, respectively, and 30-day IH-ACM was 18.6%. Five patients experienced six adverse drug reactions (one serious event: interstitial nephritis/acute kidney injury), and cefiderocol was discontinued in two cases.

Conclusion

Cefiderocol had similar clinical cure and response rates to previous retrospective studies and lower mortality. Cefiderocol was well tolerated in real-world settings in critically ill US patients with problematic Gram-negative pathogens.

Comparison of cefiderocol and colistin-based regimens for the treatment of severe infections caused by carbapenem-resistant Acinetobacter baumannii: a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

There are multiple antibiotic regimens for the treatment of carbapenem-resistant Acinetobacter baumannii (CRAB) in clinical practice. We conducted this meta-analysis to compare the efficacy and safety of cefiderocol-based regimens and colistin-based regimens in the treatment of CRAB infections.

METHODS

Two authors independently searched the PubMed, Web of Science, Embase, and Cochrane databases from their establishment to April 15, 2024, to search for randomized controlled trials (RCTs) or cohort studies, and compared the clinical efficacy and safety of cefiderocol-based regimens and colistin-based regimens in the treatment of CRAB infections. The Newcastle Ottawa Scale (NOS) checklist was used to evaluate the quality of the included studies. The primary outcome was all-cause mortality, and subgroup analysis was conducted on the basis of the site of infection and the risk of bias in the studies. Trial sequential analysis (TSA) was then conducted.

RESULTS

Six observational studies were included, with 251 cases in the cefiderocol-based group and 372 cases in the colistin-based group. Compared to the colistin-based group, the cefiderocol-based group had lower all-cause mortality (RR = 0.71, 95% CI: 0.54-0.92, P = 0.01) and 30-day mortality (RR = 0.64, 95% CI: 0.43-0.95, P = 0.03). However, for the 14-day and 28-day mortality rates, there was no statistically significant difference between two groups. According to the subgroup analysis, among patients with bloodstream infection (BSI), the cefiderocol-based group had lower all-cause mortality, but it did not reduce the mortality of ventilator-associated pneumonia (VAP) patients. The result of TSA showed that our conclusions are reliable. There was no significant statistical difference in the microbiological cure rate, clinical cure rate, or duration of hospitalization. In addition, the cefiderocol-based group did not have an increased incidence of acute kidney injury (AKI).

CONCLUSIONS

Compared with the colistin-based regimens, the cefiderocol-based regimens were significantly associated with a lower risk of mortality in CRAB-infected patients, especially for patients with BSI. However, they did not show any advantages in terms of the clinical cure rate or microbiological cure rate, nor did they reduce the incidence of AKI.

PROSPERO REGISTRATION NUMBER

CRD42023487213.

Molecular epidemiology, microbiological features and infection control strategies for carbapenem-resistant Acinetobacter baumannii in a German burn and plastic surgery center (2020-2022)

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) frequently causes both healthcare-associated infections and nosocomial outbreaks in burn medicine/plastic surgery and beyond. Owing to the high antibiotic resistance, infections are difficult to treat, and patient outcomes are often compromised. The environmental persistence capability of CRAB favors its transmission in hospitals. A comprehensive analysis and understanding of CRAB epidemiology and microbiology are essential for guiding management.

METHODS

A three-year retrospective cohort study (2020-2022) was conducted in a German tertiary burn and plastic surgery center. In addition to epidemiological analyses, microbiological and molecular techniques, including whole-genome sequencing, were applied for the comprehensive examination of isolates from CRAB-positive patients.

RESULTS

During the study period, eight CRAB cases were found, corresponding to an overall incidence of 0.2 CRAB cases per 100 cases and an incidence density of 0.35 CRAB cases per 1000 patient-days. Six cases (75%) were treated in the burn intensive care unit, and four cases (50%) acquired CRAB in the hospital. Molecular analyses comprising 74 isolates supported the epidemiologic assumption that hospital acquisitions occurred within two separate clusters. In one of these clusters, environmental CRAB contamination of anesthesia equipment may have enabled transmission. Furthermore, molecular diversity of CRAB isolates within patients was observed.

CONCLUSIONS

CRAB can pose a challenge in terms of infection prevention and control, especially if cases are clustered in time and space on a ward. Our study demonstrates that high-resolution phylogenetic analysis of several bacterial isolates from single patients can greatly aid in understanding transmission chains and helps to take precision control measures.

Use of Cefiderocol in Adult Patients: Descriptive Analysis from a Prospective, Multicenter, Cohort Study

INTRODUCTION

Cefiderocol is a siderophore cephalosporin showing activity against various carbapenem-resistant Gram-negative bacteria (CR-GNB). No data currently exist about real-world use of cefiderocol in terms of types of therapy (e.g., empirical or targeted, monotherapy or combined regimens), indications, and patient characteristics.

METHODS

In this multicenter, prospective study, we aimed at describing the use of cefiderocol in terms of types of therapy, indications, and patient characteristics.

RESULTS

Cefiderocol was administered as empirical and targeted therapy in 27.5% (55/200) and 72.5% (145/200) of cases, respectively. Overall, it was administered as monotherapy in 101/200 cases (50.5%) and as part of a combined regimen for CR-GNB infections in the remaining 99/200 cases (49.5%). In multivariable analysis, previous isolation of carbapenem-resistant Acinetobacter baumannii odds ratio (OR) 2.56, with 95% confidence interval (95% CI) 1.01-6.46, p = 0.047] and previous hematopoietic stem cell transplantation (OR 8.73, 95% CI 1.05-72.54, p = 0.045) were associated with administration of cefiderocol as part of a combined regimen, whereas chronic kidney disease was associated with cefiderocol monotherapy (OR 0.38 for combined regimen, 95% CI 0.16-0.91, p = 0.029). Cumulative 30-day mortality was 19.8%, 45.0%, 20.7%, and 22.7% in patients receiving targeted cefiderocol for infections by Enterobacterales, A. baumannii, Pseudomonas aeruginosa, and any metallo-β-lactamase producers, respectively.

CONCLUSIONS

Cefiderocol is mainly used for targeted treatment, although empirical therapies account for more than 25% of prescriptions, thus requiring dedicated standardization and guidance. The almost equal distribution of cefiderocol monotherapy and cefiderocol-based combination therapies underlines the need for further study to ascertain possible differences in efficacy between the two approaches.

Predicting early appropriate therapy for patients infected by carbapenem-resistant Gram-negative pathogens in intensive care units in Italy

BACKGROUND

Antibiotic resistance among Gram-negative bacteria in intensive care units (ICUs) is linked with high morbidity and mortality in patients. In this study, we estimated the therapeutic coverage of various antibiotics, focusing on cefiderocol and comparators, administered empirically against an infection of unknown origin in the ICU.

METHODS

In the ARTEMIS surveillance study, susceptibilities of 624 Italian Gram-negative isolates to amikacin, aztreonam-avibactam, cefiderocol, ceftazidime-avibactam, ceftolozane-tazobactam, colistin, imipenem-relebactam, meropenem, and meropenem-vaborbactam were tested by broth microdilution, and results were interpreted by European Committee on Antimicrobial Susceptibility Testing breakpoints. The susceptibility rates from the ARTEMIS study were extrapolated to Gram-negative isolates obtained from 5,774 patients in Italian ICUs in 2021. The sum of the predicted susceptibilities of individual pathogens represented the overall likelihood of in vitro activity of each antibiotic as early targeted therapy for ICU patients.

RESULTS

A total of 624 Italian Gram-negative isolates included 206 Pseudomonas aeruginosa, 138 Acinetobacter baumannii, 187 Klebsiella pneumoniae, and 93 Escherichia coli. Against A. baumannii, K. pneumoniae, P. aeruginosa, and E. coli, the overall susceptibility rates for cefiderocol were 87.7%, 96.8%, 99%, and 100%, respectively; and for comparator agents, 8.7-96.4%, 25.7-100%, 73.3-100%, and 89.2-100%, respectively. Among the subset of meropenem-resistant isolates, susceptibility rates of A. baumannii, K. pneumoniae, and P. aeruginosa to cefiderocol were 86.4%, 96.2% and 100%, respectively. Corresponding susceptibility rates to comparator agents were 0-96.8%, 0-100%, and 6.4-100%, respectively. There were no meropenem-resistant isolates of E. coli. The extrapolation of data to isolates from Italian ICUs showed that the highest likelihood of therapeutic coverage, both overall and among meropenem-resistant isolates, was reported for colistin (96.8% and 72.2%, respectively) and cefiderocol (95.7% and 71.4%, respectively). All other antibiotics were associated with a likelihood below 73% overall and between 0% and 41.4% for meropenem-resistant isolates.

CONCLUSIONS

Based on confirmed susceptibility rates and reported ICU prevalence of multiple Gram-negative species, cefiderocol showed a higher predicted therapeutic coverage and utility in ICUs compared with comparator beta-lactam-beta-lactamase inhibitor antibiotics. Cefiderocol may be a promising early treatment option for patients at high risk of carbapenem-resistant Gram-negative bacterial infections in the ICU.

Cefiderocol either in monotherapy or combination versus best available therapy in the treatment of carbapenem-resistant Acinetobacter baumannii infections: A systematic review and meta-analysis

BACKGROUND

The best treatment for carbapenem-resistant Acinetobacter baumannii (CRAB) infections is still a matter of debate.

OBJECTIVES

To describe the outcomes of patients treated with cefiderocol for CRAB infections, and to compare the efficacy of cefiderocol versus best available therapy (BAT).

DATA SOURCES

We searched MEDLINE, the Cochrane Library and EMBASE to screen original reports published up to September 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials (RCTs) and observational studies investigating 30-day mortality, clinical failure, microbiological failure or rate of adverse drug reactions of patients treated with cefiderocol or BAT.

PARTICIPANTS

Patients with infections due to CRAB.

INTERVENTIONS

Cefiderocol in monotherapy or in combination with other potentially active agents or BAT.

ASSESSMENT OF RISK OF BIAS

We used the Cochrane Risk of Bias Tool for RCTs, and the Newcastle Ottawa scale for observational studies.

METHODS OF DATA SYNTHESIS

We conducted a meta-analysis pooling risk ratios (RRs) through random effect models.

RESULTS

We screened 801 original reports, and 18 studies (2 RCTs, 13 cohort studies and 3 case-series) were included in the analysis, for a total 733 patients treated with cefiderocol, and 473 receiving the BAT. Among patients receiving cefiderocol, the 30-day mortality rate was 42% (95% CI 38-47%), the rate of microbiological failure 48% (95% CI 31-65%), the clinical failure rate 43% (95% CI 32-55%), and the rate of ADRs was 3% (95% CI 1-6%). A lower mortality rate was observed among patients receiving cefiderocol monotherapy as compared to those treated with combination regimens (RR: 0.64; 95% CI: 0.43-0.94, p = 0.024). We found a significantly lower mortality rate (RR: 0.74; 95% CI: 0.57-0.95, p = 0.02) and a lower rate of ADRs (RR: 0.28; 95% CI: 0.09-0.91, p = 0.03) in the group treated with cefiderocol as compared to BAT. No difference was observed in microbiological and clinical failure rate.

CONCLUSIONS

Our data strengthen the efficacy and safety profile of cefiderocol in CRAB infections.

Cefiderocol and Sulbactam-Durlobactam against Carbapenem-Resistant Acinetobacter baumannii

Infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) remain a clinical challenge due to limited treatment options. Recently, cefiderocol, a novel siderophore cephalosporin, and sulbactam-durlobactam, a bactericidal β-lactam-β-lactamase inhibitor combination, have been approved by the Food and Drug Administration for the treatment of A. baumannii infections. In this review, we discuss the mechanisms of action of and resistance to cefiderocol and sulbactam-durlobactam, the antimicrobial susceptibility of A. baumannii isolates to these drugs, as well as the clinical effectiveness of cefiderocol and sulbactam/durlobactam-based regimens against CRAB. Overall, cefiderocol and sulbactam-durlobactam show an excellent antimicrobial activity against CRAB. The review of clinical studies evaluating the efficacy of cefiderocol therapy against CRAB indicates it is non-inferior to colistin/other treatments for CRAB infections, with a better safety profile. Combination treatment is not associated with improved outcomes compared to monotherapy. Higher mortality rates are often associated with prior patient comorbidities and the severity of the underlying infection. Regarding sulbactam-durlobactam, current data from the pivotal clinical trial and case reports suggest this antibiotic combination could be a valuable option in critically ill patients affected by CRAB infections, in particular where no other antibiotic appears to be effective.