Phase 3, Open-label, Single-dose, Study of AAV5-hFIXco-Padua, CSL222, in Japanese Adult Male Subjects with Severe or Moderately Severe Hemophilia B

Phase 3, Open-label, Single-dose, Multicenter Study Investigating Efficacy and Safety of a Serotype 5 Adeno-associated Viral Vector Containing the Padua Variant of a Codon-optimized Human Factor IX Gene (AAV5-hFIXco-Padua, CSL222) Administered to Japanese Adult Male Subjects with Severe or Moderately Severe Hemophilia B

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

JPRN

Registry ID

JPRN-jRCT2033230266

Enrollment

Registered

2023-07-29

Start date

2023-09-28

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hemophilia B

Interventions

Single intravenous dose of CSL222 (AAV5-hFIXco-Padua

etranacogene dezaparvovec)

Eligibility

Sex/Gender

Male

Inclusion criteria

Inclusion criteria: Assigned male at birth, age >= 18 years, of Japanese origin Subject with congenital hemophilia B with known severe or moderately severe FIX deficiency ( 150 previous exposure days of FIX replacement therapy

Exclusion criteria

Exclusion criteria: History of FIX inhibitors Positive human immunodeficiency virological test Hepatitis B or C infection Known coagulation disorder other than hemophilia B

Design outcomes

Primary

Measure	Time frame
Annualized bleeding rate (ABR) for CSL222 and Lead-in FIX prophylaxis.	—

Secondary

Measure	Time frame
Efficacy 1.Endogenous FIX activity. 2.Annualized consumption of FIX replacement therapy. 3.Annualized infusion rate of FIX replacement therapy. 4.Number of subjects remaining free of continuous routine FIX prophylaxis. 5.Number of subjects with FIX activity < 12% of normal. 6.Annualized spontaneous bleeding rate. 7.Annualized joint bleeding rate. 8.ABR for FIX-treated bleeding episodes. 9.Association of FIX activity levels with pre-CSL222 AAV5 neutralizing antibody (NAb) titers. 10.Occurrence of new target joints and resolution of preexisting target joints. 11.Number of subjects with zero bleeds and zero FIX-treated bleeds. 12.Number of bleeding episodes in the first 6 months Safety 1.Adverse events. 2.Changes in liver ultrasound (every 6 months). 3.Total antibodies (immunoglobulin M and immunoglobulin G) to AAV5 and AAV5 NAbs. 4.AAV5 capsid-specific T cells. 5.Anti-FIX antibodies. 6.FIX inhibitors. 7.FIX recovery. 8.Hematology and biochemistry parameters. 9.ALT / AST levels. 10.Corticosteroid use for ALT / AST increases. 11.Vector DNA in blood and semen. 12.Inflammatory markers: interleukin 1-beta, interleukin 2, interleukin 6, interferon-gamma, monocyte chemoattractant protein-1. 13.Alpha-fetoprotein.	—

Measure

Time frame

Efficacy 1.Endogenous FIX activity. 2.Annualized consumption of FIX replacement therapy. 3.Annualized infusion rate of FIX replacement therapy. 4.Number of subjects remaining free of continuous routine FIX prophylaxis. 5.Number of subjects with FIX activity < 12% of normal. 6.Annualized spontaneous bleeding rate. 7.Annualized joint bleeding rate. 8.ABR for FIX-treated bleeding episodes. 9.Association of FIX activity levels with pre-CSL222 AAV5 neutralizing antibody (NAb) titers. 10.Occurrence of new target joints and resolution of preexisting target joints. 11.Number of subjects with zero bleeds and zero FIX-treated bleeds. 12.Number of bleeding episodes in the first 6 months Safety 1.Adverse events. 2.Changes in liver ultrasound (every 6 months). 3.Total antibodies (immunoglobulin M and immunoglobulin G) to AAV5 and AAV5 NAbs. 4.AAV5 capsid-specific T cells. 5.Anti-FIX antibodies. 6.FIX inhibitors. 7.FIX recovery. 8.Hematology and biochemistry parameters. 9.ALT / AST levels. 10.Corticosteroid use for ALT / AST increases. 11.Vector DNA in blood and semen. 12.Inflammatory markers: interleukin 1-beta, interleukin 2, interleukin 6, interferon-gamma, monocyte chemoattractant protein-1. 13.Alpha-fetoprotein.

—

Contacts

Public ContactHideto Akama

CSL Behring K.K.

JPN-CHIKEN@csl.com.au+81-3-4213-0191

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026