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Gene Therapy

Factor IX Gene Therapy for Hemophilia B (BENEGENE-2 Trial)

Phase 3
Waitlist Available
Research Sponsored by Pfizer
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Documented moderately severe to severe hemophilia B (Factor IX activity <=2%)
Suspension of prophylaxis therapy for hemophilia B after administration of the study drug
Must not have
Significant and/or unstable liver disease, biliary disease, significant liver fibrosis
Clinical signs or symptoms of decreased response to Factor IX
Timeline
Screening 3 weeks
Treatment Varies
Follow Up maximum up to 6 years (week 312) after pf-06838435 infusion
Awards & highlights
Pivotal Trial
No Placebo-Only Group

Summary

This trial tests a new gene therapy treatment for adult men with severe hemophilia B. The treatment aims to help their bodies produce a crucial blood-clotting protein. Participants will receive one dose and be monitored over several years to see if it reduces their bleeding episodes. Gene therapy for hemophilia B has shown promising results in recent studies, suggesting potential long-term therapeutic production of the coagulant protein.

Who is the study for?
Adult males with moderately severe to severe hemophilia B (Factor IX activity <=2%) who have completed at least 6 months of Factor IX prophylaxis therapy. Participants must not have antibodies against the gene therapy vector, no history of Factor IX inhibitors, and agree to contraception post-treatment.
What is being tested?
The trial is testing PF-06838435, a gene therapy intended to correct the genetic defect in hemophilia B by providing a functional copy of the Factor IX gene. Patients will receive one intravenous dose and be monitored over six years against standard prophylactic treatment.
What are the potential side effects?
Potential side effects may include immune reactions to the viral vector used for gene delivery, liver enzyme elevations indicating liver inflammation or damage, development of inhibitors (antibodies) that can neutralize Factor IX's effect, and general symptoms like fatigue or headaches.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
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My hemophilia B is severe with Factor IX activity at 2% or less.
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I will stop my preventive hemophilia B treatment after starting the study drug.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
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I do not have serious or unstable liver or biliary disease.
Select...
I show signs of not responding well to Factor IX treatments.
Select...
I am HIV positive with a CD4 count ≤200 or a viral load >20.
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I have active hepatitis B or C.
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I have or had an inhibitor to Factor IX.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~maximum up to 6 years (week 312) after pf-06838435 infusion
This trial's timeline: 3 weeks for screening, Varies for treatment, and maximum up to 6 years (week 312) after pf-06838435 infusion for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Annualized Bleeding Rate (ABR) for Total Bleeds (Treated and Untreated) From Week 12 to Month 15
Secondary study objectives
ABR for Spontaneous Bleeds From Week 12 to Month 15
ABR for Spontaneous and Traumatic, and Untreated Bleeds Through the Study
ABR for Total Bleeds (Treated and Untreated) Through the Study
+23 more

Awards & Highlights

Pivotal Trial
The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.
No Placebo-Only Group
All patients enrolled in this study will receive some form of active treatment.

Trial Design

1Treatment groups
Experimental Treatment
Group I: PF-06838435/ fidanacogene elaparvovecExperimental Treatment1 Intervention

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.
Mechanism Of Action
Side Effect Profile
Prior Approvals
Other Research
The most common treatments for Hemophilia B include gene therapy, recombinant factor IX products, and prophylactic therapies. Gene therapy, such as PF-06838435, introduces genetic material into cells to produce functional Factor IX, compensating for the missing or defective protein. This approach aims to provide a long-term solution by enabling the patient's body to produce Factor IX continuously, reducing the need for regular infusions. Recombinant factor IX products, like rFIX-FP and rFIX-GP, involve infusing synthetic Factor IX to replace the deficient protein temporarily, requiring regular administration. Prophylactic therapies involve routine infusions to maintain sufficient Factor IX levels and prevent bleeding episodes. These treatments are crucial for Hemophilia B patients as they help manage bleeding risks, improve quality of life, and reduce complications associated with the disorder.
Gene therapy for hemophilia B mediated by recombinant adeno-associated viral vector with hFIXR338A, a high catalytic activity mutation of human coagulation factor IX.

Find a Location

Who is running the clinical trial?

PfizerLead Sponsor
4,644 Previous Clinical Trials
17,743,008 Total Patients Enrolled
21 Trials studying Hemophilia B
4,937 Patients Enrolled for Hemophilia B
Pfizer CT.gov Call CenterStudy DirectorPfizer
3,532 Previous Clinical Trials
14,914,375 Total Patients Enrolled
22 Trials studying Hemophilia B
1,963 Patients Enrolled for Hemophilia B

Media Library

PF-06838435 (Gene Therapy) Clinical Trial Eligibility Overview. Trial Name: NCT03861273 — Phase 3
PF-06838435 (Gene Therapy) 2023 Treatment Timeline for Medical Study. Trial Name: NCT03861273 — Phase 3
~8 spots leftby Nov 2025
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