Phase 3 Haemophilia Trial, Recruiting

Written by an AI model from ClinicalTrials.gov eligibility criteria and checked on a sample basis. Please confirm against the original criteria.

Who might be able to join this trial:

• You must be considered a legal adult according to the laws of your country.
• You must have been born with Hemophilia B and have a severe or moderately severe lack of clotting Factor IX (FIX) — specifically, your FIX levels must be at or below 2% of normal.
• You must currently be on a regular, ongoing schedule of FIX replacement therapy (prophylaxis) to prevent bleeding.
• You must have two back-to-back blood test results that detect a certain immune marker called AAV5 neutralizing antibodies, measured during the study's early screening period.
• You must have received more than 150 days of FIX replacement therapy over your lifetime.
• You must have been on a stable, unchanged FIX prophylaxis routine for at least 2 months before the screening process begins.
• You must be able to use an electronic diary (eDiary) correctly and on time on your own, as judged by the study doctor.
• You must agree to follow the contraception (birth control) guidelines set out by the study.
• You must be able to give your informed consent — meaning you understand what the study involves and agree to take part after receiving written and verbal information about it.
• The study doctor must believe you (or your legal representative) understand the study and are able to follow all its procedures.

Who may not be able to join:

• You have a history of developing antibodies that block FIX (called FIX inhibitors), or a test during screening shows you have them now.
• Your blood test results show that your total bilirubin (a liver marker) is more than twice the upper limit of normal — unless this is caused by a harmless condition called Gilbert's syndrome.
• Your blood test results show any of the following liver, kidney, or blood abnormalities: liver enzymes ALT or AST more than twice the upper limit of normal; alkaline phosphatase (another liver marker) more than twice the upper limit of normal; creatinine (a kidney marker) more than twice the upper limit of normal; or a haemoglobin level below 8 g/dL (indicating significant anaemia).
• You have any other medical condition, apart from Hemophilia B, that causes you to bleed more easily than normal.
• Your blood platelet count is too low (below 50 × 10⁹/L), as shown in screening blood tests — platelets help your blood clot.
• You have any uncontrolled or untreated infection such as HIV, hepatitis B, or hepatitis C, or any other serious ongoing medical condition affecting your kidneys, liver, heart, blood, stomach/gut, hormones, lungs, nervous system, or mental health — including issues like alcoholism or drug dependency — that the study doctor feels would interfere with your ability to take part safely.
• You have a known allergy to corticosteroids (a type of anti-inflammatory medicine), or a medical condition that would require you to take oral corticosteroids long-term.
• You have known uncontrolled allergies, or an allergy or sensitivity to any ingredient in the study treatment (CSL222), including sucrose, potassium chloride, potassium dihydrogen phosphate, sodium chloride, or disodium hydrogen phosphate.
• You have previously received any AAV5-based gene therapy.
• You have taken part in another experimental treatment or used an experimental medical device within the 60 days before screening, or are currently doing so.

Important: Always verify eligibility with the trial site directly before applying.