Phase 3, Open-label, Single-dose Study of CSL222 in Adolescent Male Subjects with Haemophilia B
Research type
Research Study
Full title
Phase 3, Open-label, Single-dose, Multicenter Study Investigating Efficacy, Safety, and Tolerability of CSL222 (Etranacogene Dezaparvovec) Administered to Adolescent Male Subjects (≥ 12 to < 18 Years of Age) with Severe or Moderately Severe Hemophilia B
IRAS ID
1010779
Contact name
Rita Baptista
Contact email
Sponsor organisation
CSL Behring LLC
Clinicaltrials.gov Identifier
-
Research summary
Haemophilia B is an inherited bleeding disorder characterised by an increased bleeding tendency due to partial or complete deficiency of a blood coagulation protein, factor IX (FIX), resulting from mutations of the respective clotting factor gene. The researchers in this trial want to see if etranacogene dezaparvovec (CSL222), an approved gene therapy for haemophilia in male adults, is safe, works well, and is tolerated in younger patients diagnosed with severe to moderately severe haemophilia B. The aim of the study is to demonstrate that CSL222 works as well as standard of care (SoC), continuous FIX prophylaxis. CSL222 contains genetic material which can help the liver cells to produce enough FIX for the blood to clot or help cells to fix the mutated gene responsible for producing FIX normally.
The study is divided into 4 periods, (1) Screening, where the eligibility of participants will be assessed, (2) Lead-in: during this period participants will continue taking their SoC treatment which they will be asked to record along with any bleeding episode. This will continue for a minimum of 6 months and require monthly contact with the hospital, including hospital visits every other month, (3) Treatment: Participant will receive a single dose of CSL222 at the hospital, (4) 5 years follow up period: Participants will stop their standard of care treatment 7 or 14 days after the treatment period and will visit the hospital weekly for the first 12 weeks and monthly from Month 4 until Month 11, and then every 6 months from Months 12 to 60. Information on any additional treatment needed or any bleeds will be collected.
Participants will also be asked to provide blood samples, undergo physical examinations, liver ultrasounds, bone density scan’s, have X-ray’s and complete quality of life assessments and Haemophilia joint health assessments.REC name
London - Brent Research Ethics Committee
REC reference
25/LO/0314
Date of REC Opinion
11 Jun 2025
REC opinion
Further Information Favourable Opinion