CSL222 for Hemophilia B

(IX-TEND 3004 Trial)

Recruiting at 1 trial location

Age: < 18

Sex: Male

Trial Phase: Phase 3

Sponsor: CSL Behring

Must be taking: FIX prophylaxis

Disqualifiers: Thrombocytopenia, Uncontrolled infection, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Pivotal Trial (Near Approval) This treatment is in the last trial phase before FDA approval

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: Single dose

18 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new treatment called CSL222, an experimental therapy for boys with severe hemophilia B, a condition that affects blood clotting and causes frequent bleeding. The goal is to assess the safety and effectiveness of this single-dose treatment in stopping or reducing bleeding episodes. Boys with hemophilia B who have received regular treatments for at least two months might be suitable candidates. As a Phase 3 trial, this study represents the final step before FDA approval, offering participants the opportunity to contribute to a potentially groundbreaking treatment.

Do I have to stop taking my current medications for the trial?

The trial information does not specify if you need to stop taking your current medications. However, since participants must be on stable continuous FIX prophylaxis before the trial, it seems you may need to continue that specific medication.

Is there any evidence suggesting that CSL222 is likely to be safe for humans?

Studies have shown that the treatment CSL222, also known as etranacogene dezaparvovec, is generally safe. Research indicates that five years after receiving this treatment, adults with hemophilia B experienced positive safety outcomes, demonstrating long-term tolerability. Additionally, earlier findings led to the approval of this treatment for other uses, further supporting its safety. While every treatment carries potential risks, current data for CSL222 reassures its safety in humans. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Unlike the standard treatments for Hemophilia B, which often involve regular infusions of clotting factor replacements, CSL222 offers a novel approach. CSL222 is a gene therapy administered as a single intravenous infusion, which aims to provide a long-term solution by targeting the underlying genetic cause of the disease. Researchers are excited about CSL222 because it has the potential to significantly reduce or even eliminate the need for frequent factor infusions, offering patients a more sustainable and convenient treatment option.

What evidence suggests that CSL222 might be an effective treatment for hemophilia B?

Research has shown that etranacogene dezaparvovec, similar to CSL222, yields promising results for treating hemophilia B. In earlier studies, this gene therapy stabilized FIX levels (a protein needed for blood clotting) near normal in patients and reduced or eliminated the need for regular preventive treatments. These findings suggest that CSL222, which participants in this trial will receive, might increase FIX levels in the blood, helping to prevent bleeding episodes. This treatment offers hope for more consistent management of hemophilia B. ^{2 6 7 8 9}

Who Is on the Research Team?

Study Director

Principal Investigator

CSL Behring

Are You a Good Fit for This Trial?

This trial is for adolescent males aged 12 to under 18 with severe or moderately severe Hemophilia B. They must have been on stable FIX prophylaxis for at least two months and have a history of at least 75 days of treatment with FIX protein. Participants cannot join if they have abnormal blood values, uncontrolled infections, certain high antibody levels against the study drug, or any other bleeding conditions besides Hemophilia B.

Inclusion Criteria

I was assigned male at birth.

I am between 11 and 17 years old.

I am between 12 and 17 years old.

Exclusion Criteria

Screening laboratory values exceeding normal limits: Total bilirubin, ALT, AST, ALP, serum creatinine, and hemoglobin

Thrombocytopenia, defined as a platelet count below 50 × 10^9/L, at screening (based on central laboratory results)

Any uncontrolled or untreated infection or any other significant concurrent, uncontrolled medical condition as evaluated by the investigator

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Lead-In Period

Participants undergo a lead-in period to establish baseline measurements and stabilize FIX expression

At least 6 months

Treatment

Participants receive a single intravenous infusion of CSL222

Single dose

Posttreatment Follow-up

Participants are monitored for safety, efficacy, and quality of life measures

Up to 5 years

What Are the Treatments Tested in This Trial?

Interventions

• CSL222

Trial Overview The trial is testing CSL222 (AAV5-hFIXco-Padua), which is a gene therapy designed to treat Hemophilia B by delivering a functional gene to produce clotting factor IX. It's given as a single dose in an open-label setting where both researchers and participants know what treatment is being administered.

How Is the Trial Designed?

Group I: CSL222 Experimental Treatment 1 Intervention

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

Who Is Running the Clinical Trial?

CSL Behring

Lead Sponsor

Trials

204

Recruited

1,207,000+

Dr. Paul McKenzie

CSL Behring

Chief Executive Officer since 2023

PhD in Chemical Engineering from Carnegie Mellon University, B.S. in Chemical Engineering from the University of Pennsylvania

Dr. Bill Mezzanotte

CSL Behring

Chief Medical Officer since 2021

MD from Duke University

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06003387

Study Details | NCT06003387 | Efficacy and Safety of ... 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 ...

2. ashpublications.org ashpublications.org/bloodadvances/article/9/14/3543/536584/Completion-of-phase-2b-trial-of-etranacogene

Completion of phase 2b trial of etranacogene dezaparvovec ... Etranacogene dezaparvovec induced stable, sustained normal/near-normal FIX levels and eliminated the need for prophylaxis over 5 years.

3. nejm.org nejm.org/doi/full/10.1056/NEJMoa2211644

Gene Therapy with Etranacogene Dezaparvovec for ... In our study, etranacogene dezaparvovec had a favorable safety and efficacy profile in men with severe or moderately severe hemophilia B, ...

4. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12275190/

Completion of phase 2b trial of etranacogene ... Etranacogene dezaparvovec induced stable, sustained normal/near-normal FIX levels and eliminated the need for prophylaxis over 5 years.

5. labeling.cslbehring.com labeling.cslbehring.com/PI/US/Hemgenix/EN/Hemgenix-FourYear-DataReport.pdf

HEMGENIX® (etranacogene dezaparvovec-drlb) HEMGENIX is an adeno-associated virus vector-based gene therapy indicated for the treatment of adults with Hemophilia B (congenital Factor IX deficiency) who: • ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT06003387

Study Details | NCT06003387 | Efficacy and Safety of ... 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 ...

7. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/40188458/

Completion of phase 2b trial of etranacogene ... Five years after administration, etranacogene dezaparvovec was effective in adults with hemophilia B with a favorable safety profile.

8. rarediseaseadvisor.com rarediseaseadvisor.com/news/study-evaluate-csl222-efficacy-safety-hemophilia-treatment/

Study to Evaluate CSL222 Efficacy and Safety for ... A study is set to investigate the risk of bleeding due to ineffective treatment with CSL222 in adults with severe or moderately severe

9. trialfinder.panfoundation.org trialfinder.panfoundation.org/en-US/trial/listing/485297

Efficacy and Safety of CSL222 (Etranacogene ... 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 ...