Zavicefta (ceftazidime/avibactam) / Pfizer, AbbVie - LARVOL DELTA

Accurate and Sensitive UHPLC-Tandem Mass Spectrometry Sequential Methods for Therapeutic Drug Monitoring of Aztreonam/Avibactam in Human Plasma. (PubMed, Pharmaceutics) - "Clinical applicability was evaluated by reprocessing plasma samples, which were already previously collected for routine clinical practice from 20 hospitalized patients undergoing treatment with ceftazidime-avibactam plus aztreonam. Clinical application revealed substantial inter-individual variability in steady-state concentrations. The validated UHPLC-qTOF MS/MS assays provide robust and sensitive sequential quantification of aztreonam and avibactam in human plasma, supporting TDM-guided dose optimization in clinical practice."

Journal • Infectious Disease

Novel Insights into Carbapenem Resistance: Mechanisms, Diagnostics, and Future Directions. (PubMed, Antibiotics (Basel)) - "Newly introduced β-lactam/β-lactamase inhibitor combinations exert distinct selective pressures: ceftazidime-avibactam favors KPC Ω-loop variants and permeability defects, often restoring carbapenem susceptibility, whereas meropenem-vaborbactam and imipenem-relebactam resistance is driven mainly by porin loss and β-lactamase gene amplification. Cefiderocol resistance is multifactorial, frequently involving impaired siderophore uptake and heteroresistance, while sulbactam-durlobactam remains active against OXA-producing A. baumannii but is compromised by metallo-β-lactamases and PBP3 alterations...While high-level randomized evidence remains limited for some resistance mechanisms, emerging mechanistic, microbiological, and clinical data support the need for mechanism-aware diagnostics, repeated susceptibility assessment during therapy, and stewardship strategies informed by resistance biology. Integrating molecular context into routine practice will be critical to..."

Journal • Review • Infectious Disease

Ceftazidime-avibactam for multidrug and pandrug-resistant gram-negative infections in critically Ill children: a single-center pediatric ıntensive care experience. (PubMed, Eur J Pediatr) - " CZA was used as a salvage treatment in critically ill children with MDR and PDR Gram-negative infections, with favorable clinical and microbiological outcomes observed. These real-world data support its cautious incorporation into pediatric antimicrobial stewardship strategies in PICU settings."

Journal • Observational data • Retrospective data • Critical care • Infectious Disease • Pediatrics • Pneumonia

CAN RECTAL SWABS PREDICT POST-HCT PSEUDOMONAS AERUGINOSA INFECTIONS? – A PRELIMINARY SINGLE-CENTER ANALYSIS (EBMT 2026) - "Reduced intensity conditioning with Thiotepa-Fludarabine-Melphalan was more frequent among colonized patients who developed infection (66.7% vs. 27.8%, p=0.017)...Antimicrobial susceptibility patterns of rectal isolates are shown in Figure 1: susceptibility to carbapenems increased over time, likely reflecting antimicrobial stewardship interventions, whereas resistance to ceftazidime/avibactam and ceftolozane/tazobactam increased. Patients colonized with PSAE exhibited a markedly higher 30-day cumulative incidence of invasive infection compared with non-colonized patients (14.3% vs 0.98%). Rectal colonization with PSAE is strongly predict subsequent invasive infection in HCT recipients, underscoring the importance of systematic surveillance and targeted preventive strategies."

Clinical • Infectious Disease

MANAGEMENT OF BLOODSTREAM INFECTION SECONDARY TO BACTERIAL TRANSLOCATION DURING THE NEUTROPENIC PHASE OF STEM CELL TRANSPLANT. A NO–CENTRAL LINE REMOVAL STRATEGY IN 73 EPISODES (EBMT 2026) - "We assessed: 1) resolution of infection after 7 days of treatment, 2) ICU transfer, 3) recurrence of BSI with the same organism, 4) overall mortality at 30 days, and 5) the percentage of CL that was finally removed.In each episode of fever and neutropenia, a set of blood cultures was obtained, and empiric antibiotic (meropenem or ceftazidime/avibactam) was initiated within the first hour. Later, the therapy was de-escalated to cefepime according to the results and evolution... 1-More than 50% of bacteremia occurring during the neutropenic phase of SCT meet the CDC criteria of MBI-LCBI.2- Given that the central line (CL) is not the source of the infection, a strategy involving early initiation of antibiotics and salvage of the catheter is feasible and seems safe.3- This strategy saves resources and avoids invasive procedures in patients at risk of complications."

Cardiovascular • Febrile Neutropenia • Hematological Disorders • Infectious Disease • Neutropenia • Thrombosis • Transplantation

CAN RECTAL SWABS PREDICT POST-HCT PSEUDOMONAS AERUGINOSA INFECTIONS? – A PRELIMINARY SINGLE-CENTER ANALYSIS (EBMT 2026) - "Reduced intensity conditioning with Thiotepa-Fludarabine-Melphalan was more frequent among colonized patients who developed infection (66.7% vs. 27.8%, p=0.017)...Antimicrobial susceptibility patterns of rectal isolates are shown in Figure 1: susceptibility to carbapenems increased over time, likely reflecting antimicrobial stewardship interventions, whereas resistance to ceftazidime/avibactam and ceftolozane/tazobactam increased. Patients colonized with PSAE exhibited a markedly higher 30-day cumulative incidence of invasive infection compared with non-colonized patients (14.3% vs 0.98%). Rectal colonization with PSAE is strongly predict subsequent invasive infection in HCT recipients, underscoring the importance of systematic surveillance and targeted preventive strategies."

Clinical • Infectious Disease

Prognostic factors for mortality in critically ill patients with infections caused by carbapenem-resistant gram-negative pathogens treated with ceftazidime-avibactam: a multicenter retrospective study. (PubMed, BMC Infect Dis) - No abstract available

Biomarker • Journal • Retrospective data • Infectious Disease • Pneumonia

SHORTEN-II: Efficacy and safety of 7 versus 14 days of antibiotic treatment for bacteremia produced by Pseudomonas aeruginosa: a multicenter, randomized (SHORTEN-2) clinical trial with a DOOR/RADAR analysis. (clinicaltrialsregister.eu) - P4 | N=306 | Recruiting | Sponsor: Fundacion Publica Andaluza Para La Gestion De La Investigacion En Salud De Sevilla | Not yet recruiting ➔ Recruiting

Enrollment open

Comparative in vitro activity of aztreonam-avibactam and aztreonam plus ceftazidime-avibactam against Stenotrophomonas maltophilia complex. (PubMed, Antimicrob Agents Chemother) - "ATM-AVI and ATM-CZA show comparable in vitro activity against S. maltophilia complex. Isolate-level heterogeneity warrants further study of genotype-phenotype relationships."

Journal • Preclinical

Comparison between the antimicrobial activity of colistin and ceftazidime-avibactam against multidrug-resistant Pseudomonas aeruginosa isolated from patients with ventilator-associated pneumonia in intensive care units of Kasr Al-Ainy hospitals. (PubMed, BMC Infect Dis) - No abstract available

Journal • Critical care • Infectious Disease • Pneumonia • Respiratory Diseases

Diagnostic Performance of Droplet Digital PCR for Detecting Pathogens and Resistance Genes in Patients with Suspected Bloodstream Infections. (PubMed, Infect Drug Resist) - "Based on the rapid ddPCR results, the antimicrobial therapy was adjusted to ceftazidime/avibactam (2.5 g q8h) to target the pathogen. This case showed that ddPCR could reduce the time to diagnosis and promotes precise antibiotic use. The clinical value of ddPCR is to detect and quantify pathogens and resistance genes early to provide appropriate guidance for therapeutic options."

Journal • Infectious Disease • Pneumonia

Clinical and genomic determinants associated with emergent ceftazidime-avibactam plus aztreonam non-susceptibility in ceftazidime-avibactam resistant Escherichia coli. (PubMed, Antimicrob Agents Chemother) - "We performed a comprehensive clinical and genomic analysis of ceftazidime-avibactam-resistant Escherichia coli (CZA-R-Ec) collected at a tertiary cancer center (2017-2024) to identify patient- and isolate-level factors associated with reduced susceptibility to ATM/CZA and aztreonam-avibactam (AZA). In conclusion, CZA-R-Ec at our center are dominated by PBP3-insertion, blaNDM-5-positive lineages, for which ATM/CZA retains substantial in vitro activity and clinical efficacy. However, prior E. coli infection and blaCMY-42 variant positivity identify patients at risk for ATM/CZA non-susceptible infections."

Journal • Infectious Disease • Oncology

Real-World Evidence and Multidrug Resistant Infections: How Can We Leverage RWE to Improve Patient Outcome with the Novel Beta-Lactam and Beta-Lactam/Beta-Lactamase Inhibitor Combinations. (PubMed, Infect Drug Resist) - "A comprehensive literature search was performed on PubMed-MEDLINE from January 2015 to September 2025 for identifying pivotal trials and real-world evidence concerning the use of cefiderocol and of novel beta-lactam/beta-lactamase inhibitor combination (BL/BLIc) including those of tomorrow (ie, ceftolozane-tazobactam, ceftazidime-avibactam, meropenem-vaborbactam, imipenem-relebactam, cefepime-enmetazobactam, cefepime-taniborbactam, cefepime-zidebactam, sulbactam-durlobactam, aztreonam-avibactam). Real-world evidence concerning both well-designed observational studies and PK/PD models may represent a mandatory tool for overcoming issues associated with pivotal trials evaluating novel BL/BLIc. The implementation of dedicated well-designed real-world studies would be warranted for ensuring a constant update of proposed therapeutic algorithms."

HEOR • Journal • Real-world evidence • Review • Infectious Disease

Comparative outcomes of ceftazidime-avibactam versus meropenem-vaborbactam for KPC-producing Enterobacterales infections. (PubMed, Antimicrob Agents Chemother) - "Thirty-day mortality was similar in a propensity-score-weighted cohort of 73 patients with KPC-producing Enterobacterales infections treated with ceftazidime-avibactam or meropenem-vaborbactam. Emergence of resistance was higher in the ceftazidime-avibactam group (12% vs 0%); putative resistance mechanisms included porin mutations (Klebsiella pneumoniae) and R2 loop structural changes in AmpC (Enterobacter cloacae complex)."

Journal • Infectious Disease • Pneumonia

Within-host evolution of emerging ceftazidime/avibactam resistance in Pseudomonas aeruginosa via ampC overexpression and attenuated virulence (ESCMID Global 2026) - No abstract available

Late-breaking abstract

When in vitro meets in vivo: therapeutic role of ceftazidime/avibactam & aztreonam in metallo-β-lactamase-producing, colistin-resistant Klebsiella pneumoniae and Pseudomonas aeruginosa: a five-case translational experience (ESCMID Global 2026) - No abstract available

Preclinical • Infectious Disease • Pneumonia

Real-world use of ceftazidime/avibactam plus aztreonam in children with MBL-producing Gram-negative infections (ESCMID Global 2026) - No abstract available

Clinical • Gram negative • Real-world • Real-world evidence • Infectious Disease

Ampicillin/sulbactam and ceftazidime/avibactam for the treatment of carbapenem-resistant Acinetobacter baumannii complex: correlation of genotype, phenotype, and clinical outcomes (ESCMID Global 2026) - No abstract available

Clinical • Clinical data

SY160 - Emerging resistance to new antibiotics: are we already losing the newest tools? (ESCMID Global 2026) - "This session explores the troubling rise of resistance to recently approved antibiotics, including cefiderocol, ceftazidime-avibactam, imipenem/relebactam, cefepime-taniborbactam, aztreonam-avibactam, etc. Although these drugs were introduced as critical last-resort options against multidrug-resistant infections, reports of resistance have emerged within just a few years of clinical use. The panel will address the urgent need for improved stewardship, faster diagnostics, and equitable access to new antibiotics to preserve their effectiveness. Participants will gain insights into how resistance spreads, how policies impact antimicrobial use, and what strategies might still help us stay ahead in the race against resistant pathogens."

Infectious Disease

Efficacy of ceftazidime/avibactam and ceftolozane/tazobactam in combination with colistin or fosfomycin against difficult-to-treat Pseudomonas aeruginosa strains: an in vitro pharmacodynamic study (ESCMID Global 2026) - No abstract available

Combination therapy • PK/PD data • Preclinical

Impact of ceftazidime/avibactam plus aztreonam on mortality in metallo-β-lactamase-producing Enterobacterales bloodstream infections: a propensity score-matched analysis (ESCMID Global 2026) - No abstract available

Infectious Disease

Comparative effectiveness of ceftazidime/avibactam, meropenem/vaborbactam, and imipenem/relebactam for multidrug-resistant Gram-negative bloodstream infections: a retrospective cohort study (ESCMID Global 2026) - No abstract available

Gram negative • HEOR • Retrospective data • Infectious Disease

Outcomes of MBL-producing Pseudomonas aeruginosa vs Enterobacterales bloodstream infections treated with ceftazidime/avibactam plus aztreonam: a multi-centre study, Chile, 2019–2025 (ESCMID Global 2026) - No abstract available

Clinical • Infectious Disease

Use of ceftazidime/avibactam for multidrug-resistant Gram-negative infections in neonates and children: real-world experience from a tertiary care hospital in Argentina (ESCMID Global 2026) - No abstract available

Clinical • Gram negative • Real-world • Real-world evidence • Infectious Disease

Broad-spectrum in vitro activity of ceftazidime/avibactam/aztreonam against Klebsiella pneumoniae with diverse resistance mechanisms (ESCMID Global 2026) - No abstract available

Preclinical • Infectious Disease • Pneumonia