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Study on the Effectiveness of Concizumab for Children Under 12 with Hemophilia A or B, With or Without Inhibitors

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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 the effects of a medication called Concizumab in children under 12 years old who have Hemophilia A or Hemophilia B, with or without inhibitors. Hemophilia is a condition where the blood does not clot properly, leading to excessive bleeding. Inhibitors are substances that can interfere with the treatment of hemophilia. The medication being tested, Concizumab, is given as an injection under the skin using a special pen-injector device.

The purpose of the study is to see how well Concizumab works in preventing bleeding episodes compared to the previous treatment the children were receiving. The study will involve children who have not used Concizumab before. Participants will receive regular injections of Concizumab over a period of time, and the number of bleeding episodes they experience will be monitored and compared to their previous treatment.

Throughout the study, researchers will also keep track of any side effects or reactions to the medication, such as injection site reactions or the development of antibodies against Concizumab. The study aims to provide valuable information on the safety and effectiveness of Concizumab in managing bleeding episodes in young children with hemophilia.

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, informed consent is required. This means understanding the study and agreeing to participate.

    Eligibility is based on a diagnosis of severe haemophilia A or B, with or without inhibitors, and being under 12 years of age.

  2. Step 2

    Treatment initiation

    The treatment involves the use of concizumab, a medication administered as a solution for injection under the skin (subcutaneous).

    The specific dosage forms available are 40 mg/mL, 100 mg/mL, and 10 mg/mL.

  3. Step 3

    Treatment duration

    The treatment is ongoing and will continue until the primary analysis cut-off, which is determined by the study's timeline.

    The study aims to compare the effectiveness of concizumab in reducing bleeding episodes compared to previous treatments.

  4. Step 4

    Monitoring and assessments

    Throughout the study, the number of bleeding episodes, both spontaneous and traumatic, will be recorded.

    Additional assessments include monitoring for any adverse events, such as reactions at the injection site or the development of antibodies to concizumab.

  5. Step 5

    End of study

    The study is estimated to conclude by November 2029.

    Final assessments will be conducted to evaluate the overall effectiveness and safety of the treatment.

Who can join the trial?

6 criteria

  • Must have given permission to participate in the study. This means agreeing to take part after understanding what the study involves.
  • Must have a diagnosis of **congenital severe haemophilia A** (a condition where the blood doesn't clot properly due to very low levels of a protein called factor VIII) or **moderate/severe congenital haemophilia B** (similar condition but due to low levels of factor IX), or have haemophilia with **inhibitors** (substances that prevent clotting treatments from working).
  • For one part of the study: Must be a boy under 12 years old at the time of agreeing to participate.
  • For boys with inhibitors: Must have medical records showing at least 26 weeks of treatment for bleeding episodes in the past year. This treatment involves using products that help blood clot.
  • For boys without inhibitors: Must have medical records showing at least 52 weeks of treatment for bleeding episodes in the past year, with at least 3 treated bleeding episodes documented. Alternatively, must have at least 26 weeks of preventive treatment in the past year.
  • For another part of the study: Must be a male patient who has previously been treated with a medication called **concizumab** through a special program.

Who cannot join the trial?

3 criteria

  • Children who are not male cannot participate in the study.
  • Children who do not have **Haemophilia A or B** cannot participate. Haemophilia is a condition where the blood does not clot properly, leading to excessive bleeding.
  • Children who are 12 years or older cannot participate in the study.
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Investigated drugs

Concizumab is a medication being studied for its ability to prevent bleeding episodes in children under 12 years old who have hemophilia A or B. This medication is being tested to see if it can reduce the number of bleeding episodes compared to the treatment the children were receiving before. The study includes children with and without inhibitors, which are substances that can make it harder for some treatments to work.

What is already known about the treatment

Concizumab – Concizumab is administered as an injection under the skin, designed to be used regularly to prevent bleeding episodes. It is currently being studied in clinical trials, particularly for its effectiveness and safety in children under 12 years old with Hemophilia A or B, with or without inhibitors. The main therapeutic use of concizumab is to reduce the frequency of bleeding episodes in these patients. At the molecular level, concizumab works by inhibiting a protein called tissue factor pathway inhibitor (TFPI), which plays a role in the regulation of blood clotting. It is classified as an anticoagulant therapy, specifically targeting the blood clotting process to prevent excessive bleeding.

Investigated diseases

  • Hemophilia A

    Hemophilia A is a genetic disorder where the blood does not clot properly due to a deficiency of clotting factor VIII. This condition leads to prolonged bleeding after injuries, surgeries, or even spontaneously without any apparent cause. Individuals with hemophilia A may experience frequent nosebleeds, easy bruising, and joint bleeding, which can cause pain and swelling. Over time, repeated joint bleeding can lead to joint damage. The severity of bleeding episodes can vary, with some individuals experiencing more frequent and severe episodes than others.

  • Hemophilia B

    Hemophilia B is a genetic bleeding disorder caused by a deficiency of clotting factor IX. Similar to hemophilia A, this condition results in prolonged bleeding after injuries or surgeries and can also cause spontaneous bleeding episodes. People with hemophilia B may experience symptoms such as frequent nosebleeds, easy bruising, and bleeding into joints and muscles. Joint bleeding can lead to pain, swelling, and over time, joint damage. The severity of symptoms can vary, with some individuals experiencing more frequent and severe bleeding episodes.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-506925-13-00Protocol codeNN7415-4616Estimated enrolment153 patientsSponsorNovo Nordisk A/S

sourced from the EU Clinical Trials Register and site verification

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