Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

RecruitingRare disease

Study on Personalized Dosing of Emicizumab for Patients with Congenital Hemophilia A

Fast replyRegistered drug
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

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

This clinical trial is focused on studying a condition known as congenital hemophilia A, a genetic disorder that affects the blood's ability to clot properly, leading to excessive bleeding. The treatment being investigated is called emicizumab, which is a type of medication known as a humanized monoclonal antibody. Emicizumab is administered as a solution for injection under the skin, known as a subcutaneous injection. The study aims to determine if a personalized dosing approach, guided by the levels of the drug in the blood, is as effective as the standard dosing method in preventing bleeding episodes in patients with congenital hemophilia A.

Participants in the study will receive emicizumab, which is also known by its code names RO5534262 and ACE910. The study will compare two dosing strategies: the conventional dosing and a new approach that adjusts the dose based on how the drug is processed in the body, known as pharmacokinetic-guided dosing. The goal is to see if the personalized dosing can prevent treated bleeds, spontaneous joint or muscle bleeds, and overall bleeding as effectively as the conventional method.

The study will take place over several months, during which participants will be monitored for bleeding events and other health indicators. The trial will also assess the quality of life, joint health, and any pain experienced during the administration of emicizumab. By the end of the study, researchers hope to gather valuable information on the effectiveness and potential benefits of personalized dosing for individuals with congenital hemophilia A.

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

    Initial phase

    Upon joining the study, the patient will continue their current treatment with emicizumab, a medication used to prevent bleeding in individuals with congenital haemophilia A.

    The medication is administered as a subcutaneous injection, which means it is injected under the skin.

    The dosage is 6 mg per kilogram of body weight every four weeks. This phase lasts for 12 months and is intended to ensure stability in bleeding control.

  2. Step 2

    Bleeding assessment phase

    During this phase, the patient's bleeding events are closely monitored over a period of 6 months.

    The goal is to assess the frequency and severity of any bleeding episodes, including joint or muscle bleeds.

    This information is crucial for evaluating the effectiveness of the current dosing regimen.

  3. Step 3

    Pharmacokinetic-guided dosing phase

    In this phase, the dosing of emicizumab is adjusted based on pharmacokinetic data, which involves understanding how the drug is processed in the body.

    The aim is to tailor the dosage to the individual needs of the patient, potentially improving the prevention of bleeding.

    This phase also lasts for 6 months, during which the patient's response to the adjusted dosing is evaluated.

  4. Step 4

    Dose continuation phase

    Following the pharmacokinetic-guided dosing phase, the patient continues with the adjusted dosing regimen for an additional 6 months.

    The focus remains on maintaining effective bleeding control and monitoring any changes in the patient's condition.

    Throughout this phase, regular assessments are conducted to ensure the treatment remains effective and safe.

  5. Step 5

    Final evaluation

    At the end of the study, a comprehensive evaluation is conducted to compare the outcomes of the conventional dosing and the pharmacokinetic-guided dosing.

    The primary measure is the proportion of patients without treated bleeds during the different phases.

    Secondary measures include the frequency of spontaneous joint or muscle bleeds, the annualized bleeding rate, and the overall health-related quality of life.

Who can join the trial?

7 criteria

  • Have a confirmed diagnosis of **congenital haemophilia A**, which is a bleeding disorder present from birth, with a specific blood factor level (FVIII) of less than 6 IU/mL.
  • Be older than 1 year at the time of joining the study.
  • Have been receiving a specific treatment called **emicizumab** at a conventional dose for at least 12 months before joining the study.
  • Have good control over bleeding, meaning no unexpected joint or muscle bleeds in the last 6 months and no more than two treated bleeds due to injury in the last 6 months.
  • Be willing and able to provide written consent to participate, either by the patient or their parents/legal guardian.
  • Be willing to provide information about any bleeding episodes.
  • Be willing to follow the medication schedule as required by the study.

Who cannot join the trial?

4 criteria

  • Patients who do not have **congenital haemophilia A**. This is a condition where a person is born with a problem in their blood that makes it hard to stop bleeding.
  • Patients who are female, as the study is only for male participants.
  • Patients who are not within the specified age range for the study. The study is for certain age groups, so if you are too young or too old, you may not be able to participate.
  • Patients who belong to a vulnerable population. This means people who might need extra protection or care, like those with certain disabilities or conditions.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Emicizumab is a medication used in this study to help prevent bleeding in patients with congenital hemophilia A. It works by mimicking the action of a protein that helps blood to clot, which is missing or not working properly in people with this condition. The study is exploring whether adjusting the dose of Emicizumab based on how the body processes the drug (pharmacokinetic-guided dosing) is as effective as the standard dosing method in preventing bleeding episodes.

What is already known about the treatment

Emicizumab – Emicizumab is administered as an injection under the skin, typically on a weekly basis. It is currently used in the treatment of congenital Hemophilia A, a condition characterized by a deficiency in clotting factor VIII. Emicizumab works by mimicking the function of factor VIII, bridging activated factor IX and factor X, which helps in the blood clotting process. It is classified as a monoclonal antibody and is well-documented in medical literature for its role in reducing bleeding episodes in patients with Hemophilia A.

Investigated diseases

Congenital Hemophilia A – This is a genetic disorder characterized by a deficiency in clotting factor VIII, which is essential for blood clotting. Individuals with this condition experience prolonged bleeding or spontaneous bleeding episodes, particularly in joints and muscles. The severity of bleeding can vary, with some individuals experiencing frequent and severe bleeds, while others may have milder symptoms. Bleeding episodes can lead to joint damage over time if not managed properly. This condition is typically diagnosed in early childhood, often after a significant bleeding event. It is a lifelong condition that requires careful management to prevent bleeding complications.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase ITrial ID2024-515528-35-00Protocol code22-571/21U-0151Estimated enrolment135 patientsSponsorUniversitair Medisch Centrum Utrecht

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

ClinicalTrials.eu

Every clinical trial in Europe, in plain language.

Explore the full ecosystem of clinical research in Europe.

Search trials

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).