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Study on Baloxavir Marboxil for Children with Influenza

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

This clinical trial is focused on studying Influenza, commonly known as the flu, in children. The treatment being tested is a medication called Baloxavir Marboxil, which is also known by its code name S-033188. This medication is provided in the form of granules that are mixed with liquid to create an oral suspension, making it easier for children to take.

The purpose of the study is to understand how well Baloxavir Marboxil works in treating the flu in children and to observe any changes in the flu virus that might occur during treatment. The study will monitor children who have been diagnosed with the flu and will involve taking samples at different times to check for any changes in the virus. These samples will help researchers see if the virus becomes resistant to the medication.

Participants in the study will receive the medication and will be observed over a short period. The study will involve several visits where samples will be collected to monitor the virus and any side effects of the medication. The goal is to gather information on how the flu virus responds to Baloxavir Marboxil and to ensure the safety and effectiveness of the treatment in children.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Participation begins after confirmation of influenza through a positive test. This test must be conducted within 24 hours before the study screening.

    A negative test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is required within 48 hours before the study screening.

    The onset of influenza symptoms must be within 48 hours before the start of pre-dose examinations.

  2. Step 2

    Initial assessment

    Pre-dose examinations are conducted to assess the presence of resistance-associated substitutions in the influenza virus. This is done on Day 1.

  3. Step 3

    Medication administration

    The medication used in this study is baloxavir marboxil, administered as an oral suspension called Xofluza.

    The dosage and frequency of administration are determined by the study protocol and are specific to each participant.

  4. Step 4

    Follow-up assessments

    Follow-up assessments are conducted on Days 4, 6, and 10 to monitor the incidence of resistance-associated treatment-emergent substitutions.

    These assessments help determine the effectiveness of the medication and any changes in the influenza virus.

  5. Step 5

    Additional evaluations

    Secondary evaluations include monitoring the incidence of novel mutations, the type and subtype of the influenza virus, and the viral load at various time points.

    The susceptibility of the virus to baloxavir marboxil is also assessed through phenotyping of samples.

  6. Step 6

    Monitoring adverse events

    Throughout the study, any adverse events or serious adverse events are recorded and evaluated for severity.

    The severity is determined according to established criteria to ensure participant safety.

Who can join the trial?

6 criteria

  • Patients must have symptoms that suggest they have the flu, and this must be confirmed by a positive flu test. This test can be a rapid flu test, a Liat® test, or a PCR test. In the European Union, the test must follow specific regulations.
  • Patients must have a negative test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the virus that causes COVID-19. This test can also be a rapid test, a Liat® test, or a PCR test, and must be done within 48 hours before the full study screening.
  • The time between when flu symptoms start and when the first study examinations begin must be 48 hours or less.
  • Patients, or their parents or caregivers, must be able to understand the study, follow all study procedures, and be willing to sign a written agreement to participate before the first study examinations.
  • Both male and female patients can participate in the study.
  • The study includes patients who may be considered vulnerable, meaning they might need extra care or protection.

Who cannot join the trial?

7 criteria

  • Patients who have a known allergy or severe reaction to the study medication or any of its ingredients.
  • Patients who are currently participating in another clinical trial or have participated in one within the last 30 days.
  • Patients with a history of severe liver or kidney disease, as these conditions may affect how the body processes the medication.
  • Patients who are pregnant or breastfeeding, as the effects of the medication on unborn babies or infants are not fully known.
  • Patients with a compromised immune system, which means their body's defense against infections is weakened.
  • Patients who have received a live vaccine within the last 4 weeks, as this may interfere with the study medication.
  • Patients with any other medical condition that the study doctors believe would make it unsafe for them to participate.
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Investigated drugs

Baloxavir Marboxil is a medication used in this clinical trial to treat pediatric patients with influenza. It works by inhibiting the replication of the influenza virus, helping to reduce the severity and duration of flu symptoms. The study aims to evaluate how the virus may develop resistance to this medication in children.

What is already known about the treatment

Baloxavir Marboxil – This medication is administered orally and is used to treat influenza. It is currently being studied in clinical trials, particularly in pediatric patients, to understand its effectiveness and resistance patterns. Baloxavir Marboxil is primarily indicated for the treatment of influenza and works by inhibiting the polymerase acidic protein, which is essential for viral replication. It belongs to the class of antiviral medications, specifically targeting the influenza virus to reduce its ability to multiply and spread.

Investigated diseases

Influenza – Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. It primarily affects the nose, throat, and sometimes the lungs. Symptoms often include fever, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue. The virus spreads through droplets when an infected person coughs, sneezes, or talks. Influenza can lead to mild to severe illness, and its progression can vary depending on the individual's age, health status, and the specific strain of the virus. The flu season typically occurs in the fall and winter months, with varying levels of activity each year.
Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase IIITrial ID2023-504672-22-00Protocol codeCV44536Estimated enrolment610 patientsSponsorF. Hoffmann-La Roche AG

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