Phase 3, Open-label, Single-dose Study of CSL222 in Adolescent Male Subjects (≥ 12 to < 18 Years of Age) With Severe or Moderately Severe Hemophilia B
This research study is investigating a new, single-dose treatment called CSL222 for adolescent males aged 12 to under 18 years old who have severe or moderately severe haemophilia B. Haemophilia B is a condition where your blood doesn't clot properly, leading to longer bleeding. CSL222 is designed to help the body make more of the clotting factor it needs. The study aims to see how well CSL222 works by checking if it reduces bleeding episodes, and also to make sure it's safe for participants. This is a "Phase 3" study, which means it's one of the final steps before a treatment might become widely available, building on earlier research.
At a glance
What is this study about?
Haemophilia B is a lifelong condition that mainly affects males. If you have haemophilia B, your body doesn't produce enough of a protein called Factor IX (FIX), which is essential for blood clotting. This means you might bleed for longer after an injury or even experience spontaneous bleeding inside your body, particularly in your joints, which can be painful and cause long-term damage. Current treatments often involve regular injections of FIX, but researchers are always looking for new ways to manage the condition more easily and effectively.
This study, called a Phase 3 trial, is looking at a new treatment called CSL222. It's designed to be a one-time injection that helps your body produce its own Factor IX. The goal is to reduce how often you have bleeding episodes and potentially allow you to need fewer regular treatments. Because it's a Phase 3 study, it means the treatment has already been tested in earlier stages and shown promise, and now researchers want to confirm its benefits and safety in a larger group of people.
Throughout the study, participants will be carefully monitored. The researchers will be checking important health markers, how often bleeds occur, and any side effects. This thorough approach helps them understand if CSL222 is a good and safe option for treating haemophilia B in teenagers.
Key takeaways
- Targets teenage boys (12 to under 18) with severe or moderately severe haemophilia B.
- Investigates a new single-dose treatment called CSL222.
- Aims to help the body make its own Factor IX to reduce bleeding.
- Requires a 6-month 'lead-in' period before treatment.
- Involves regular safety checks and monitoring after treatment.
- Participation is voluntary, and you can withdraw anytime.
Who may be eligible?
This study is specifically looking for teenage boys who have severe or moderately severe haemophilia B. You would need to be between 12 and under 18 years old when you receive the study treatment. Before that, for the initial checks, you can be between 11 and a half years old and just over 17 years old.
You should have been diagnosed with haemophilia B where your Factor IX levels are 2% or less of normal. You also need to have been on a stable, regular treatment plan (called prophylaxis) for your haemophilia B for at least two months before joining, and have had many previous treatments with Factor IX protein.
There are also some reasons why you wouldn't be able to join. For example, if you've ever had an "inhibitor" to Factor IX (where your body creates antibodies against the treatment), or if certain blood tests show unusual results, especially related to your liver or kidneys. You also can't take part if you have other serious medical conditions or uncontrolled infections.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- Are you a male, aged between 12 and under 18 years old?
- Do you have severe or moderately severe haemophilia B (Factor IX levels 2% or less)?
- Have you been on a stable, regular Factor IX treatment for at least two months?
- Have you had many previous treatments with Factor IX protein?
- Have you never had an 'inhibitor' (where your body fights against Factor IX treatment)?
- Are your recent blood test results (for liver, kidney, etc.) within acceptable limits?
What does participation involve?
If you join this study, it actually starts with a "lead-in period" lasting at least six months. During this time, the researchers will collect information about your current haemophilia B treatment and bleeding episodes before you even receive the new study medicine. After this period, if you still meet all the criteria, you would receive a single dose of the CSL222 treatment. This means no more regular injections for the study drug after that first one.
Throughout the study, you'll have regular hospital visits for check-ups. These visits will involve blood tests to monitor your Factor IX levels and overall health, physical examinations, and discussions about any bleeding episodes you've had or how you're feeling. The medical team will closely watch for any side effects and make sure you're safe. While the specific number of visits and their duration will be explained by the study team, the total commitment will involve ongoing monitoring for a significant period after receiving the single dose.
Potential risks and benefits
Locations (12)
- Center for Inherited Blood DisordersVerified postcodeOrange, United States· Recruiting
- University of FloridaVerified postcodeGainesville, United States· Recruiting
- Arthur M. Blank Hospital - Children's Healthcare of AtlantaVerified postcodeAtlanta, United States· Recruiting
- University of Michigan Medical CenterVerified postcodeAnn Arbor, United States· Recruiting
- St. Jude Children's Research HospitalVerified postcodeMemphis, United States· Recruiting
- Medical University ViennaVerified postcodeVienna, Austria· Recruiting
- UZ Leuven - Centrum voor Moleculaire en Vasculaire BiologieVerified postcodeLeuven, Belgium· Recruiting
- Chaim Sheba Medical CenterVerified postcodeRamat Gan, Israel· Recruiting
- Hospital Sant Joan de DéuVerified postcodeBarcelona, Spain· Recruiting
- La Paz University HospitalVerified postcodeMadrid, Spain· Recruiting
- St Thomas HospitalVerified postcodeLondon, United Kingdom· Recruiting
- John Radcliffe Hospital - Oxford University Hospitals NHSVerified postcodeOxford, United Kingdom· Recruiting
Common questions
What is CSL222?
CSL222 is a new type of medicine being tested that aims to help your body produce its own Factor IX, a protein needed for blood clotting, to treat haemophilia B.
How is CSL222 given?
Unlike regular Factor IX injections, CSL222 is designed to be given as a single injection, meaning you would only receive it once during the study.
Will I stop my current haemophilia B treatment if I join?
Initially, you'll continue your current treatment during a monitoring period. If you receive CSL222, the study team will guide you on how that might change your regular Factor IX treatment plan.
What does 'Phase 3' study mean?
A Phase 3 study is one of the final stages of research before a new medicine might be approved. It means the treatment has already shown promise and is being tested in more people to confirm its safety and effectiveness.
Can girls participate in this study?
No, this specific study is only looking for adolescent males diagnosed with haemophilia B.
How to find out more
Trial Registration Coordinator
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
Discussion
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