Efficacy and Safety of CSL222 (Etranacogene Dezaparvovec) Gene Therapy in Adults With Hemophilia B With Pretreatment Adeno-associated Virus Serotype 5 (AAV5) Neutralizing Antibodies (Nabs)

NCT ID: NCT06003387

Last Updated: 2025-12-12

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE3

Total Enrollment

35 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-01-30

Study Completion Date

2032-04-02

Brief Summary

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The purpose of this study is to assess the risk of bleeding due to failure of expected pharmacological action of CSL222 in adults with severe or moderately severe hemophilia B with detectable pretreatment AAV5 Nabs.

Detailed Description

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Conditions

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Hemophilia B

Study Design

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Allocation Method

NA

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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CSL222

Participants will receive CSL222 as a single intravenous (IV) infusion of 2 × 10\^13 genome copies per kilogram (gc/kg) on Day 1.

Group Type EXPERIMENTAL

CSL222 (AAV5-hFIXco-Padua)

Intervention Type GENETIC

Administered as a single IV infusion.

Interventions

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CSL222 (AAV5-hFIXco-Padua)

Administered as a single IV infusion.

Intervention Type GENETIC

Other Intervention Names

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Etranacogene dezaparvovec

Eligibility Criteria

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Inclusion Criteria

* nd considered legally an adult, as defined by country regulations.
* •Has congenital hemophilia B with known severe or moderately severe FIX deficiency (less than or equal to \[\<=\] 2% of normal circulating FIX) for which the participant is on continuous routine FIX prophylaxis.
* • Has 2 consecutive detectable AAV5 NAb titer results between Screening and Visit L-Final using a validated AAV5 NAb assay (based on central laboratory results).
* • Has greater than (\>) 150 previous exposure days to FIX replacement therapy.
* • Has been on stable FIX prophylaxis for at least 2 months before Screening.
* • Has demonstrated capability to independently, accurately, and in a timely manner complete the eDiary during the Lead-in Period, as judged by the investigator.
* • Acceptance to adhere to contraception guidelines.
* • Able to provide informed consent after receipt of verbal and written information about the study.
* • Investigator believes that the participant (or the participant's legally acceptable representative\[s\]) understands the nature, scope, and possible consequences of the study and is able to adhere to the study procedures.

Exclusion Criteria

* • History of FIX inhibitors or positive FIX inhibitor test at Prescreening, Screening or Visit L-Final (based on central laboratory results).
* • Screening or Visit L-Final laboratory values (based on central laboratory results) of total bilirubin \> 2 × the upper limit of normal (ULN) (except if caused by Gilbert's syndrome).
* • Screening or Visit L-Final laboratory values (based on central laboratory results) of any of the following laboratory abnormalities:
* a) ALT \> 2 × the ULN
* b) AST \> 2 × the ULN
* c) Alkaline phosphatase \> 2 × the ULN
* d) Serum creatinine \> 2 × the ULN
* e) Hemoglobin less than (\<) 8 g/dL
* • Any condition other than hemophilia B resulting in an increased bleeding tendency.
* • Thrombocytopenia, defined as a platelet count \<50 × 10\^9/L, at Screening or Visit L Final (based on central laboratory results).
* • Any uncontrolled or untreated infection (human immunodeficiency virus \[HIV\], hepatitis B virus \[HBV\] and hepatitis C virus \[HCV\], or any other significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, cardiovascular, hematological, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease, alcoholism, drug dependency, or any other psychological disorder evaluated by the investigator to interfere with adherence to the clinical study protocol procedures or with the degree of tolerance to CSL222.
* • Known history of allergy to corticosteroids or known medical condition that would require chronic administration of oral corticosteroids.
* • Known uncontrolled allergic conditions or allergy / hypersensitivity to any component of the CSL222 excipients (ie, sucrose, potassium chloride, potassium dihydrogen phosphate, sodium chloride, and disodium hydrogen phosphate).
* • Previous AAV5 gene therapy treatment.
* • Receipt of an experimental agent or device within 60 days before Screening until the end of the study.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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CSL Behring

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Study Director

Role: STUDY_DIRECTOR

CSL Behring

Locations

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University of California, San Diego (UCSD) - 84000460

San Diego, California, United States

Site Status RECRUITING

University of Michigan - 84000285

Ann Arbor, Michigan, United States

Site Status RECRUITING

Royal Prince Alfred Hospital - 03600044

Camperdown, New South Wales, Australia

Site Status RECRUITING

Royal Brisbane Hospital - 03600045

Herston, Queensland, Australia

Site Status RECRUITING

Royal Adelaide Hospital

Adelaide, South Australia, Australia

Site Status RECRUITING

The Alfred Hospital - 03600043

Melbourne, Victoria, Australia

Site Status RECRUITING

McMaster University - Hamilton - 12400017

Hamilton, Ontario, Canada

Site Status RECRUITING

Queen Mary Hospital - 34400001

Hong Kong, , Hong Kong

Site Status RECRUITING

Prince of Wales Hospital Chinese University of Hong Kong - 34400002

Shatin, , Hong Kong

Site Status RECRUITING

Sheba Medical Center - 37600004

Tel Litwinsky, , Israel

Site Status RECRUITING

Centro de Investigacion Clinica GRAMEL S.C. - 48400003

Mexico City, Mexico City, Mexico

Site Status RECRUITING

King Faisal Specialist Hospital and Research Center - 68200001

Riyadh, , Saudi Arabia

Site Status RECRUITING

National University Hospital - 70200002

Singapore, , Singapore

Site Status RECRUITING

Haemophilia Comprehensive Care Centre - 71000001

Johannesburg, , South Africa

Site Status RECRUITING

Kyungpook National University Hospital - 41000014

Daegu, , South Korea

Site Status RECRUITING

Kyung Hee University Hospital at Gangdong - 41000015

Seoul, , South Korea

Site Status RECRUITING

Severance Hospital, Yonsei University Health System - 41000013

Seoul, , South Korea

Site Status RECRUITING

Tri-Service General Hospital - 15800012

Taipei, Neihu District, Taiwan

Site Status RECRUITING

Kaohsiung Medical University Chung-Ho Memorial Hospital (KMUH) - 15800011

Kaohsiung City, Sanmin District, Taiwan

Site Status RECRUITING

Changhua Christian Hospital (CCH) - 15800009

Chang-hua, , Taiwan

Site Status RECRUITING

Taichung Veterans General Hospital - 15800007

Taichung, , Taiwan

Site Status RECRUITING

National Taiwan University Hospital

Taipei, , Taiwan

Site Status RECRUITING

Ege University Medical Faculty - 79200002

Bornova, , Turkey (Türkiye)

Site Status RECRUITING

Gaziantep University Sahinbey Research and Practice Hospital - 79200004

Gaziantep, , Turkey (Türkiye)

Site Status RECRUITING

Özel Acibadem Adana Hastanesi - 79200003

Seyhan, , Turkey (Türkiye)

Site Status RECRUITING

Countries

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United States Australia Canada Hong Kong Israel Mexico Saudi Arabia Singapore South Africa South Korea Taiwan Turkey (Türkiye)

Central Contacts

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Trial Registration Coordinator

Role: CONTACT

1-610-878-4697

Facility Contacts

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Other Identifiers

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2023-509590-23-00

Identifier Type: CTIS

Identifier Source: secondary_id

CSL222_3005

Identifier Type: -

Identifier Source: org_study_id

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