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Evaluation of NXT007 versus Emicizumab Prophylaxis in Patients with Hemophilia A

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

Hemophilia A is a rare condition in which the blood does not clot properly, leading to frequent bleeding episodes that can affect joints and other parts of the body. The study examines two preventive medicines: a new product called NXT007, which is a laboratory‑made antibody that helps the blood clot, and an existing treatment called Emicizumab. Both medicines are given by a small needle under the skin, known as a subcutaneous injection, and are intended to reduce the number of bleeding episodes.

The purpose of the trial is to determine whether NXT007 works at least as well as Emicizumab in preventing bleeds. Participants receive regular injections for several months and attend scheduled visits where doctors check their health, collect blood samples, and ask about daily activities and quality of life. The main way the study measures success is by counting the average number of bleeding episodes that need treatment each year, called the annualized number of treated bleeds.

Throughout the study, safety is closely watched. Researchers look for any side effects such as reactions at the injection site, allergic responses, or signs of clotting problems. Participants also complete simple questionnaires about how their condition affects everyday life, helping to assess both the medical and personal impact of the treatments.

The research process

The trial runs in 8 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Enrollment and randomization

    After providing informed consent, you will undergo baseline medical assessments and be assigned randomly to receive either nxt007 or emicizumab prophylaxis.

  2. Step 2

    Baseline assessments

    You will have a physical examination, laboratory tests, and complete a quality of life questionnaire to establish baseline values.

  3. Step 3

    Initiation of study medication

    You will receive the assigned study drug by subcutaneous injection.

    The dose and injection frequency are defined by the study protocol and are not disclosed here; the medication will be administered throughout the study period.

  4. Step 4

    Month 2 visit – start of primary efficacy collection

    From this visit onward, the primary endpoint, the annualized number of treated bleeds (abr), will be recorded until the clinical cutoff date.

    You will continue to record any bleeds and receive study medication as scheduled.

  5. Step 5

    Regular follow‑up visits

    You will attend scheduled visits (typically monthly) for safety assessments, injection training, and collection of blood samples.

    Blood samples will be analyzed for plasma concentration of the study drug and for the presence of anti‑drug antibodies.

    Adverse events, injection‑site reactions, and any signs of thrombotic complications will be evaluated at each visit.

  6. Step 6

    Month 8 visit – quality of life assessment

    You will complete the quality of life questionnaire again to assess changes since baseline.

  7. Step 7

    Ongoing monitoring of safety and efficacy

    Throughout the trial you will be instructed to report any adverse events, including severe hypersensitivity, anaphylaxis, or thromboembolic events.

    The study team will track the number of injections and dose per bleed of any additional coagulation factors or bypassing agents you may require.

  8. Step 8

    Final study visit

    At the end of the study period, you will undergo final assessments, including a final quality of life questionnaire, blood sampling for drug concentration and antibody testing, and a summary of bleeding episodes.

    The study medication will be discontinued after this visit.

Who can join the trial?

6 criteria

  • Have a confirmed diagnosis of severe or moderate congenital Hemophilia A (a genetic bleeding disorder) based on blood levels of factor VIII: severe means less than 1 IU/dL, moderate means 1‑5 IU/dL, and you may or may not have inhibitors (antibodies) against factor VIII.
  • Have laboratory test results for factor VIII inhibitors that were done within the past 12 months.
  • Provide medical records that show details of regular (preventive) and occasional factor VIII treatments, any use of bypassing agents (medicines that help clotting when factor VIII does not work), use of emicizumab preventive treatment, and the number and type of bleeding episodes during the last 6 months.
  • If you are currently using treatment only when bleeding occurs (on‑demand therapy), you must agree to switch to a regular preventive treatment with either emicizumab or NXT007 as assigned by the study.
  • Agree to follow the study’s contraception requirements (use birth control as instructed).
  • Be either male or female and belong to an age group allowed by the study (children, adolescents, or adults).

Who cannot join the trial?

6 criteria

  • If you have an allergy to any part of the study drug, the tests, or any ingredient, you cannot join the trial.
  • If you are currently taking medicines that change the whole immune system (systemic immunomodulators) such as interferon or rituximab, or plan to start them during the study (except medicines used to treat HIV called antiretroviral therapy), you are not eligible.
  • If you would refuse to receive plasma-derived or other blood product transfusion support in an emergency, you cannot participate.
  • If you have a planned surgery during the study period (except very minor procedures like a simple tooth extraction or a small incision to drain an infection), you are excluded.
  • If you have a history of abnormal heart rhythms in the lower chambers of the heart (ventricular dysrhythmias) or risk factors such as structural heart disease (for example, a very weak main pumping chamber called severe left ventricular systolic dysfunction or a thickened heart muscle called left ventricular hypertrophy) or coronary heart disease (narrowed heart arteries that cause chest pain or reduced blood flow, known as ischemia), you cannot join.
  • If you have an abnormal result on an ECG (a test that records the heart’s electrical activity) that is considered important—such as a complete left bundle branch block or a second- or third-degree atrioventricular heart block—or if you have had a previous myocardial infarction (heart attack), you are not eligible.
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Investigated drugs

  • NXT007

    is a laboratory‑engineered antibody that attaches to two proteins involved in blood clotting, called factor IXa and factor X. By linking these proteins, it helps the blood form clots even in people who lack the normal clotting factor needed for hemophilia A. In the trial, participants receive NXT007 as a subcutaneous injection (a shot under the skin) on a regular schedule to try to prevent bleeding episodes.

  • Hemlibra (emicizumab)

    is a medication that also works like a bridge between factor IXa and factor X, helping the blood clot more normally in people with hemophilia A. It is given as a subcutaneous injection and is used as a preventive (prophylaxis) treatment to reduce the number of bleeds. In this study, Hemlibra serves as the comparison treatment to see how well NXT007 works.

What is already known about the treatment

  • NXT007

    NXT007 is given as a solution for subcutaneous injection, meaning it is injected under the skin. It is a humanised IgG4 monoclonal antibody that is still being studied and is not yet approved for general medical use. The drug is designed to help people with hemophilia A by linking two blood‑clotting proteins, factor VIII and factor X, to improve clot formation. It belongs to the class of bispecific antibodies that act as clotting factor mimetics.

  • Hemlibra

    Hemlibra (emicizumab) is supplied as a 150 mg/mL solution for subcutaneous injection, allowing patients to give themselves the medicine under the skin. It is an approved medication that is already used in clinical practice for hemophilia A. The drug works by connecting clotting factor IX and factor X, acting like missing factor VIII to help blood clot normally. It is classified as a bispecific monoclonal antibody that mimics factor VIII activity.

Investigated diseases

Hemophilia A - Hemophilia A is a hereditary disorder in which the blood lacks enough clotting factor VIII. Because of this shortage, blood does not clot normally, so bleeding lasts longer after cuts or injuries. People with the condition often experience bruising, nosebleeds, and bleeding into muscles or joints. Repeated joint bleeds can cause swelling, pain, and reduced movement over time. The disorder is present from birth and may become more noticeable as a person becomes more active.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-522435-33-00Protocol codeBO45887Estimated enrolment360 patientsSponsorF. Hoffmann-La Roche AG

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