Emblaveo (aztreonam/avibactam) / Pfizer, AstraZeneca, AbbVie - LARVOL DELTA

Breaking the deadlock of metallo-β-lactamases: evidence and prospects for Aztreonam/Avibactam. (PubMed, Emerg Microbes Infect) - "It is important to note that the combination of ceftazidime/avibactam (CZA) with ATM differs significantly from AZA in pharmacokinetic properties. The primary mechanisms of resistance involve mutations in the PBP3 gene, mutations and overexpression of β-lactamases, reduced outer membrane permeability, and overexpression of efflux pumps. Available data suggest that AZA is an important treatment option for severe infections caused by multidrug-resistant Enterobacterales, including MBL-producing strains, although pharmacoeconomic conclusions remain context-dependent."

Journal • Review • Infectious Disease • Pneumonia • Respiratory Diseases

Newer antibiotics for drug-resistant Gram-negative infections in immunocompromised hosts: from pivotal trials to high-risk practice. (PubMed, Front Cell Infect Microbiol) - "This critical narrative Review integrates 27 pivotal-trial protocol identifiers included in a predefined evidence map, immune-phenotype-specific cohorts, contemporary guidance, pharmacokinetic/pharmacodynamic evidence, and treatment-emergent resistance reports for a bounded core set of newer agents first authorized in the United States or European Union between 2014 and 2025, including newer β-lactam/β-lactamase-inhibitor combinations, cefiderocol, sulbactam-durlobactam, aztreonam-avibactam, and selected non-β-lactams. The Review then synthesizes treatment by resistance mechanism and applies a host-pathogen-drug-context framework to empirical selection, diagnostics, exposure optimization, source control, de-escalation, relapse, and resistance. The resulting evidence map supports mechanism-active therapy while making the limits of transfer auditable and defining priorities for standardized phenotype reporting and pragmatic enrollment."

Journal • Review • Hematological Disorders • Hematological Malignancies • Human Immunodeficiency Virus • Immunology • Infectious Disease • Neutropenia • Oncology • Pediatrics • Primary Immunodeficiency • Solid Organ Transplantation • Solid Tumor • Transplantation

Escherichia coli with penicillin-binding protein 3 insertions: implications for newer β-lactam/β-lactamase inhibitor combinations. (PubMed, Antimicrob Agents Chemother) - "Newer β-lactam/β-lactamase inhibitor combinations (ceftazidime/avibactam, aztreonam/avibactam, and cefepime/taniborbactam) and cefiderocol with affinities for PBP3 show reduced activity against E. coli with YRIN and YRIK insertions...In contrast, agents targeting PBP2, such as cefepime/zidebactam and cefiderocol-xeruborbactam, retain potent in vitro activity and will likely be important for future treatment strategies...There is an urgent need for enhanced global surveillance, along with rapid diagnostic tools capable of identifying PBP3 insertions and associated high-risk clones among carbapenemase-producing E. coli. Future strategies should prioritize agents with activities against multiple essential PBPs to preserve β-lactam efficacy."

Journal • Review

A Four-Center Study on the Activity of Aztreonam and Aztreonam-Avibactam Combination Against Clinical Isolates of Gram-Negative Bacilli Producing Representatives of Ambler Class A, B, C or D β-Lactamases. (PubMed, APMIS) - "However, aztreonam-avibactam resistance may be encountered in a considerable portion of carbapenem-resistant E. coli isolates. High aztreonam-avibactam MIC values suggest limited in vitro activity of aztreonam-avibactam against MBL-producing P. aeruginosa isolates in this collection."

Journal • Infectious Disease • Pneumonia

Aztreonam-Avibactam Activity against Carbapenem-Resistant Enterobacterales from United States Medical Centers Stratified By year and Resistance Mechanism (2021-2025). (IDWeek 2026) - No abstract available

Infectious Disease

Ex-Vivo Modeling and Simulation to Guide Aztreonam-Avibactam Dosing Recommendations for Patients Receiving Continuous Renal Replacement Therapy (CRRT) (IDWeek 2026) - No abstract available

Preclinical • Infectious Disease

Inhibiting Multiple Penicillin-Binding-Proteins with Novel β-lactam Combinations is a Clinically Viable Therapeutic Strategy to Overcome Aztreonam-Avibactam and Cefiderocol Resistance in Metallo-β-lactamase Producing Enterobacterales (IDWeek 2026) - No abstract available

Clinical • Infectious Disease

Antimicrobial Activity of Aztreonam-Avibactam against Enterobacterales Isolated from Patients with Ventilator-Associated Pneumonia (VAP) (IDWeek 2026) - No abstract available

Clinical • Infectious Disease

Aztreonam-Avibactam Activity against Gram-negative Bacteria Isolated from Patients Hospitalized with Pneumonia in United States Medical Centers (2023–2025) (IDWeek 2026) - No abstract available

Clinical • Gram negative • Infectious Disease

Aztreonam-avibactam activity against Enterobacterales from United States medical centers: Summary of 5 years of surveillance prior to approval for clinical use (2020-2024) (IDWeek 2026) - No abstract available

Clinical • Infectious Disease

In-Vitro Activity of Aztreonam–Avibactam Against NDM-Producing Enterobacterales Isolated from Sterile Site Clinical Specimens in a Tertiary Care Cancer Hospital (IDWeek 2026) - No abstract available

Preclinical • Infectious Disease

Emerging Extended-Spectrum β-Lactamases (CMY in E. coli, PER in K. pneumoniae) Plus PBP3 Alterations Drive Aztreonam-Avibactam Resistance in Metallo-β-Lactamase-Producing Enterobacterales via Species-Specific Pathways (IDWeek 2026) - No abstract available

Infectious Disease

Ex-Vivo Modeling and Simulation to Guide Aztreonam-Avibactam Dosing Recommendations for Patients Receiving Continuous Renal Replacement Therapy (CRRT) (IDWeek 2026) - No abstract available

Preclinical • Infectious Disease

Aztreonam-Avibactam Activity against Carbapenem-Resistant Enterobacterales from United States Medical Centers Stratified By year and Resistance Mechanism (2021-2025). (IDWeek 2026) - No abstract available

Infectious Disease

Aztreonam/avibactam during continuous venovenous haemodiafiltration in a critically ill patient with NDM-producing Klebsiella pneumoniae: a case report and review of the literature. (PubMed, Infection) - "The case demonstrates the practical feasibility of continuous-infusion aztreonam/avibactam during CVVHDF. Efficacy and PK/PD target attainment cannot be confirmed, as susceptibility testing for the index strain and therapeutic drug monitoring were unavailable."

Journal • Chronic Kidney Disease • Infectious Disease • Nephrology • Pneumonia • Renal Disease • Septic Shock

Aztreonam-avibactam Activity against Enterobacterales from Asia Pacific and Latin American Medical Centres: Summary of 5 years of Surveillance prior to Clinical Use (2020-2024). (PubMed, Int J Antimicrob Agents) - "The results of this investigation provide a baseline for monitoring the activity of aztreonam-avibactam in APAC and LATAM and emphasize the importance of surveillance programs to monitor the emergence of resistance markers."

Journal • Infectious Disease • Pneumonia

Impact of PBP3 insertions and β-lactamase-encoding genes on the susceptibility of Escherichia coli isolates belonging to high-risk clones against aztreonam-avibactam and comparator agents. (PubMed, Antimicrob Agents Chemother) - "Resistance to aztreonam-avibactam is multifactorial, and singular resistance mechanisms are unable to elevate MIC values to resistant categories. Additionally, lineage-specific contributions to resistance play an important role in the overall development of β-lactam resistance, although these mechanisms appear to function outside the known repertoire of resistance-conferring mutations and warrant further study."

Journal

Avibactam-based combinations for the treatment of multidrug resistant Gram-negative bacilli infections. (PubMed, Infez Med) - "Ceftazidime/avibactam has become a cornerstone for the treatment of infections caused by KPC-producing Enterobacterales, whereas the recent availability of aztreonam/avibactam has provided the first targeted option against metallo-β-lactamase (MBL)-producing Enterobacterales. Aztreonam/avibactam represents the first-line option for the treatment of MBL-producing Enterobacterales and plays a pivotal role in the current era of increasing dissemination of multiple carbapenemases. Their optimal clinical positioning should rely on optimal use in empirical therapy in patients with rectal colonization with carbapenem-resistant Enterobacterales who develop sepsis or septic shock, antimicrobial stewardship principles and integration of local epidemiology, microbiological data and patient characteristics to maximize efficacy while preserving their long-term activity."

Journal • Review • Infectious Disease • Septic Shock

Efficacy of new antimicrobial agents against carbapenemase-producing and non-carbapenemase-producing carbapenem-resistant Enterobacterales in Japan: national genomic surveillance (JARBS 2.0) study. (PubMed, J Antimicrob Chemother) - "Nacubactam-based combinations, cefiderocol and aztreonam/avibactam show promise against MBL-producing Enterobacterales in Japan, whereas cefepime/nacubactam demonstrated the greatest activity against non-CP CRE. The upgraded JARBS 2.0 framework enables high-resolution genomic and phenotypic surveillance, bridging the gap between molecular resistance mechanisms and the clinical efficacy of emerging antimicrobial agents. These findings highlight the value of integrating genomic surveillance into routine monitoring to guide antimicrobial therapy and inform infection prevention and control strategies."

Journal • Infectious Disease

In vitro potency of novel ertapenem/zidebactam combination (WCK 6777) against carbapenemase-producing Enterobacterales collected across India. (PubMed, JAC Antimicrob Resist) - "MICs of ertapenem/zidebactam and comparator agents (carbapenems, imipenem/relebactam, ceftazidime/avibactam and aztreonam/avibactam) were determined by broth microdilution method. The enhanced activity of ertapenem/zidebactam is attributed to zidebactam's dual mechanism, β-lactamase inhibition and high-affinity PBP2 binding, enabling effective coverage despite complex resistance mechanisms. Its once-daily dosing supports its potential as an OPAT-enabling therapeutic option and warrant further clinical development."

Journal • Preclinical • Infectious Disease • Pneumonia

"One Health"-based epidemiological investigation reveals the emergence of carbapenem-resistant Morganella spp. across diverse ecological niches. (PubMed, J Glob Antimicrob Resist) - "CRM occur across multiple One Health niches. The findings highlight environmental and non-human reservoirs as potential contributors to their dissemination and identify blaPER-4 and aac(3)-IV as resistance-associated genes requiring further study."

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Phage-first treatment results in subpopulation-driven collateral sensitivity to beta-lactams in an extensively drug-resistant Pseudomonas aeruginosa. (PubMed, Antimicrob Agents Chemother) - "Static time-kill studies (STKS) evaluated the LPS-specific phage PYO2 in combination with either aztreonam/avibactam (ATM/AVI) or polymyxin B (PMB) against an extensively drug-resistant clinical isolate of P. aeruginosa (AR-0231)...Altogether, our study provides mechanistic insights into phage-induced collateral sensitivity of beta-lactams. These results show how specific beta-lactams can be prioritized and optimized in phage-antibiotic combinations to maximize the antibacterial activity."

Journal • Infectious Disease

Aztreonam-Avibactam Successfully Treated Severe Stenotrophomonas maltophilia Infection After Allogeneic Transplantation: A Case Report and Literature Reviews. (PubMed, J Blood Med) - "The patient was smoothly transferred from the transplant ward to a general ward. Aztreonam-avibactam may have a very good clinical effect on patients with severe and multi-site Stenotrophomonas maltophilia infections."

Journal • Bone Marrow Transplantation • Gastrointestinal Disorder • Hematological Malignancies • Infectious Disease • Leukemia • Oncology • Septic Shock • Transplantation

Stenotrophomonas maltophilia in the Antimicrobial Resistance Era: Species-Complex Taxonomy, Pathogenesis, Evolving Therapeutic Priorities, and Genomic Surveillance. (PubMed, Infect Drug Resist) - "Current IDSA guidance identifies cefiderocol monotherapy as the preferred treatment for invasive S. maltophilia infection, whereas aztreonam-avibactam and agents such as trimethoprim-sulfamethoxazole, levofloxacin, and minocycline occupy alternative or combination-based roles. Nevertheless, the therapeutic evidence base remains uneven, and clinical decisions should integrate infection severity, source control, susceptibility findings, pharmacokinetic/pharmacodynamic (PK/PD) exposure, toxicity, infection site, and host-related factors. This review summarizes advances in taxonomy, epidemiology, pathogenesis, diagnostics, resistance, treatment, infection prevention, and genomic surveillance, and highlights the need for standardized identification, validated breakpoints, prospective comparative-effectiveness studies, and pragmatic or adaptive trial designs."

Journal • Review • Infectious Disease

Antimicrobial activity of aztreonam/avibactam and molecular characterization of Enterobacterales not susceptible to ceftazidime/avibactam and/or meropenem/vaborbactam from US medical centres (2016-2024). (PubMed, J Antimicrob Chemother) - "Aztreonam/avibactam demonstrated potent activity against isolates not susceptible to ceftazidime/avibactam and/or meropenem/vaborbactam as well as against CRE isolates, including MBL producers. The activities of other β-lactamase inhibitor combinations and cefiderocol were adversely affected by the alarming increase of MBL producers in some US hospitals."

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