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:

To enter the first part of the trial (the Lead-in Period):

• People who were assigned male sex at birth
• People who are between 11 years and 6 months old, and 17 years and 2 months old, at the time of signing consent
• People who were born with hemophilia B and have a severe or moderately severe lack of a clotting protein called Factor IX (FIX), meaning their FIX levels are 2% or less of normal, and who have been on ongoing FIX replacement treatment
• People who have been on a stable, regular FIX treatment schedule for at least 2 months before the screening visit
• People who have received at least 75 previous treatment sessions with FIX protein before screening

To enter the second part of the trial (the Treatment Period):

• People who have completed at least 6 months (26 weeks) of the Lead-in Period, with eligibility confirmed at that point
• People who are between 12 and 17 years old at the time of receiving the trial treatment CSL222

Who may not be able to join:

During the Lead-in Period:

• People who have a history of developing antibodies (called inhibitors) that work against FIX, or who test positive for these inhibitors at screening
• People whose blood test results at screening show that certain liver markers (bilirubin, ALT, AST, or ALP) or a kidney marker (creatinine) are more than twice the normal upper limit, or whose haemoglobin (a measure of red blood cells) is below 8 g/dL
• People who have another medical condition, separate from haemophilia B, that also causes increased bleeding
• People who have a low platelet count (below 50 × 10⁹/L) at screening, as platelets help the blood to clot
• People who have an uncontrolled or untreated infection (such as HIV or hepatitis C), or any other significant uncontrolled medical condition affecting the kidneys, liver, heart, blood, digestive system, hormones, lungs, nervous system, brain, or mental health, or who have issues with alcohol or drug dependency — as assessed by the trial doctor

During the Treatment Period:

• People who test positive for FIX inhibitors at the final Lead-in visit
• People whose blood test shows a high level of antibodies to a virus called AAV5 (a level above 1:900), measured near the end of the Lead-in Period (confirm with trial site)
• People whose blood test results at the final Lead-in visit show the same out-of-range liver, kidney, red blood cell, or platelet values described above for the Lead-in Period

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