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Study of Aztreonam-Avibactam and Metronidazole for Children with Serious Gram-Negative Bacterial Infections

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

The study involves children from 9 months to under 18 years who have serious Gram-negative bacterial infections. These infections can appear as Hospital-acquired pneumonia, Ventilator-associated pneumonia, Complicated intra-abdominal infection, Complicated urinary tract infection, Bloodstream infection, or as Sepsis. The experimental treatment is a combination of Aztreonam-Avibactam given intravenous (through a vein), sometimes together with Metronidazole. Participants receive this new regimen or the best available therapy, which are the standard antibiotics normally used for these serious infections.

The purpose of the study is to evaluate the pharmacokinetics (PK) – how the medicine moves through the body – as well as safety and how well it is tolerated. Children will be treated for a short period, with blood samples taken to check drug levels and regular checks of liver and kidney function. After the treatment ends, follow‑up visits will assess whether the infection has cleared and whether any side effects occurred.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, you will be assigned to one of two groups. One group will receive the combination of aztreonam-avibactam and metronidazole, while the other group will receive the best available therapy for your condition.

  2. Step 2

    Treatment administration

    If you are in the group receiving aztreonam-avibactam, you will receive this medication through an intravenous (IV) infusion. This means the medicine will be given directly into your vein. The dosage and frequency will be determined by the study team based on your specific needs.

    If you are in the group receiving the best available therapy, the specific medications, their dosages, and frequency will be determined by the study team based on your condition.

  3. Step 3

    Monitoring and assessments

    Throughout the study, your health will be closely monitored. This includes regular assessments of your liver and kidney functions, as well as checking for any side effects or adverse reactions to the medications.

    Blood samples will be taken on Day 1 and at steady state (Day 2 or later) to measure the levels of aztreonam and avibactam in your blood.

  4. Step 4

    End of treatment

    At the end of the treatment period, your clinical outcomes will be evaluated. This includes assessing how well the infection has responded to the treatment.

    Microbiological tests will be conducted to determine the response of the bacteria to the treatment.

  5. Step 5

    Follow-up

    After completing the treatment, there will be a follow-up period to monitor your recovery and ensure there are no lingering effects from the infection or the treatment.

Who can join the trial?

8 criteria

  • Participants must be between 9 months to less than 18 years of age at the time of screening.
  • Female participants who have started menstruating must have a negative pregnancy test.
  • Participants must have a suspected or confirmed infection such as:
    • Complicated Intra-abdominal Infection (cIAI): A serious infection inside the belly area.
    • Complicated Urinary Tract Infection (cUTI): A serious infection in the urinary system.
    • Hospital-Acquired Pneumonia (HAP) or Ventilator-Associated Pneumonia (VAP): Lung infections acquired in a hospital setting.
    • Blood Stream Infection (BSI): An infection in the blood.
    • The infections must be caused by gram-negative bacteria, a type of bacteria that can cause serious infections.
    • Participants must require hospitalization and treatment with intravenous (IV) antibiotics, which means receiving medicine directly into a vein.

Who cannot join the trial?

7 criteria

  • Participants must not have any other serious infections that are not related to the study.
  • Participants should not have any known allergies to the study medication or its components.
  • Participants must not be currently participating in another clinical trial.
  • Participants should not have any medical conditions that the study doctors believe would make it unsafe for them to participate.
  • Participants must not be pregnant or breastfeeding.
  • Participants should not have a history of drug or alcohol abuse that could interfere with the study.
  • Participants must not have any condition that affects their ability to understand or follow study instructions.
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Investigated drugs

  • Aztreonam-Avibactam

    is a combination of two medications used to treat serious bacterial infections. Aztreonam is an antibiotic that works by killing bacteria, while Avibactam helps Aztreonam work better by preventing bacteria from breaking it down. This combination is given through a vein and is used to treat infections caused by certain types of bacteria that are hard to treat with other antibiotics.

  • Metronidazole

    is an antibiotic that is used to treat infections caused by bacteria and parasites. It works by stopping the growth of bacteria and parasites. In this trial, Metronidazole is used alongside Aztreonam-Avibactam to help treat complicated infections in the abdomen, which is the area of the body that contains the stomach and other digestive organs.

What is already known about the treatment

Aztreonam-Avibactam – This medication is administered intravenously, meaning it is given directly into a vein through an injection. It is currently being studied in clinical trials for its effectiveness and safety in treating serious gram-negative bacterial infections in children aged 9 months to less than 18 years. The main therapeutic indications include urinary tract infections, ventilator-associated pneumonia, bloodstream infections, hospital-acquired pneumonia, sepsis, intra-abdominal infections, and other complicated gram-negative bacterial infections. At the molecular level, Aztreonam works by disrupting the bacterial cell wall, while Avibactam helps prevent bacteria from breaking down Aztreonam, making the combination more effective. This medication is classified as an antibiotic, specifically targeting gram-negative bacteria.

Investigated diseases

  • Urinary Tract Infection

    A urinary tract infection (UTI) is an infection that affects any part of the urinary system, including the kidneys, ureters, bladder, and urethra. It typically begins when bacteria enter the urinary tract through the urethra and multiply in the bladder. Symptoms often include a strong, persistent urge to urinate, a burning sensation during urination, and cloudy or strong-smelling urine. If the infection spreads to the kidneys, it can cause back pain, fever, and nausea. UTIs are more common in women than men. They can recur, especially in women who have had them before.

  • Ventilator-Associated Pneumonia

    Ventilator-associated pneumonia (VAP) is a lung infection that occurs in people who are on mechanical ventilation breathing machines in hospitals. It develops when bacteria enter the lungs through the ventilator tube. Symptoms include fever, increased white blood cell count, purulent sputum, and a new or progressive infiltrate on chest X-ray. VAP can lead to difficulty breathing and reduced oxygen levels in the blood. It is a common complication in patients receiving mechanical ventilation. The risk of VAP increases with the duration of mechanical ventilation.

  • Blood Stream Infection

    A bloodstream infection (BSI) occurs when bacteria or fungi enter the bloodstream, leading to a systemic inflammatory response. It can originate from infections in other parts of the body, such as the lungs, urinary tract, or skin. Symptoms may include fever, chills, rapid breathing, and an increased heart rate. BSIs can lead to widespread inflammation and organ dysfunction if not addressed. They are often associated with the use of medical devices like catheters. Prompt identification and management are crucial to prevent complications.

  • Hospital-Acquired Pneumonia

    Hospital-acquired pneumonia (HAP) is a lung infection that occurs 48 hours or more after admission to a hospital and was not present at the time of admission. It is caused by bacteria that are often resistant to antibiotics. Symptoms include cough, fever, chills, and difficulty breathing. HAP can lead to decreased oxygen levels and respiratory distress. It is a significant cause of morbidity in hospitalized patients. The risk of developing HAP increases with prolonged hospital stays and the use of mechanical ventilation.

  • Sepsis

    Sepsis is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. It can result from infections in the lungs, urinary tract, skin, or other areas. Symptoms include fever, increased heart rate, increased breathing rate, and confusion. Sepsis can progress to severe sepsis and septic shock, characterized by a significant drop in blood pressure. It requires prompt medical attention to prevent organ failure. Early recognition and intervention are critical in managing sepsis.

  • Intra-abdominal Infection

    Intra-abdominal infections occur within the abdominal cavity and can involve organs such as the stomach, intestines, liver, or pancreas. They often result from perforations, abscesses, or inflammation of the abdominal organs. Symptoms may include abdominal pain, fever, nausea, and vomiting. These infections can lead to peritonitis, an inflammation of the peritoneum, which can cause severe abdominal pain and tenderness. Intra-abdominal infections can spread rapidly and require timely intervention. They are often associated with surgical procedures or trauma.

Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IITrial ID2022-501575-12-00Protocol codeC3601008Estimated enrolment54 patientsSponsorPfizer Inc.

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