Different dosing schedules of ceftazidime‑avibactam plus aztreonam for carbapenem‑resistant Gram‑negative infections

A Clinical Study on Sequential Infusion Versus Concomitant Infusion of Ceftazidime-avibactam Combined With Aztreonam for the Treatment of Metallo-β-lactamase-producing Carbapenem-resistant Gram-negative Bacterial Infections.

This trial tests different dosing schedules of ceftazidime‑avibactam plus aztreonam to see which works best for adults with metallo‑β‑lactamase–producing, carbapenem‑resistant Gram‑negative infections.

Quick facts

• Phase: Phase 4
• Study type: Interventional
• Enrollment: 144 (estimated)
• Ages: 18 Years to 100 Years
• Sex: All
• Sponsor: The First Affiliated Hospital with Nanjing Medical University (Academic / other)
• Locations: 1 site (Nanjin, Jiangsu)
• Trial ID: NCT07478484 on ClinicalTrials.gov

What this trial studies

This Phase 4 interventional trial compares different administration regimens of ceftazidime‑avibactam combined with aztreonam in adults with infections caused by metallo‑β‑lactamase–producing, carbapenem‑resistant Gram‑negative bacteria. Eligible patients have serious infections such as complicated intra‑abdominal infection, hospital‑ or ventilator‑associated pneumonia, complicated urinary tract infection, or bloodstream infection confirmed by genotypic testing. Participants receive the antibiotic combination according to assigned dosing schedules and are followed for clinical, microbiological, and safety outcomes. The study is conducted in a real‑world hospital setting to inform optimal dosing where therapeutic options are limited.

Who should consider this trial

Good fit: Adults (≥18 years) with cIAI, HAP/VAP, cUTI, or bloodstream infection confirmed to be due to metallo‑β‑lactamase–producing carbapenem‑resistant Gram‑negative bacteria who are treated with ceftazidime‑avibactam plus aztreonam.

Not a fit: Patients under 18, pregnant or breastfeeding individuals, those with severe hypersensitivity to β‑lactam antibiotics, or patients without MBL‑producing CR‑GNB infections are unlikely to benefit.

Why it matters

Potential benefit: If successful, it could identify administration strategies that improve cure rates and survival for patients with otherwise hard‑to‑treat MBL‑producing carbapenem‑resistant Gram‑negative infections.

How similar studies have performed: Multiple real‑world and clinical reports have shown that combining aztreonam with avibactam‑containing regimens can be synergistic and reduce infection‑related mortality against MBL‑producers, though randomized controlled data are limited.

Eligibility criteria

Inclusion Criteria:

1. Patients diagnosed with complicated intra-abdominal infection (cIAI), hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP), complicated urinary tract infection (cUTI), or bloodstream infection (BSI);
2. Patients with confirmed infections caused by metallo-β-lactamase-producing carbapenem-resistant Gram-negative bacteria (MBL-CR-GNB), as determined by genotypic testing using next-generation sequencing (NGS) or carbapenem resistance gene testing;
3. Patients receiving treatment with ceftazidime-avibactam in combination with aztreonam.

Exclusion Criteria:

1. Patients aged under 18 years;
2. Patients with known hypersensitivity to ceftazidime, avibactam, aztreonam, or any of the excipients; or those with a history of severe hypersensitivity reactions (e.g., anaphylactic shock, severe skin reactions) to any other β-lactam antibacterial agents (such as penicillins, monobactams, or carbapenems);
3. Pregnant or breastfeeding women;
4. Patients unable to comprehend or comply with the study protocol;
5. Any other condition which, in the investigator's discretion, makes the patient unsuitable for participation in the trial.

Where this trial is running

Nanjin, Jiangsu

• Jing Zhou — Nanjin, Jiangsu, China (Recruiting)

Conditions Ceftazidime-avibactam; Aztreonam; Gram-negative Bacterial Infection; Metallo-β-lactamase-producing; Carbapenem-resistant