What side effects are associated with this type of intervention?

Common treatments for Hemophilia B include gene therapy, such as PF-06838435, which introduces genetic material to compensate for missing or non-functioning Factor IX. Known side effects of gene therapy can include immune responses to the introduced viral vectors, liver enzyme elevations, and potential long-term risks such as insertional mutagenesis. Other treatments like recombinant factor IX products may cause allergic reactions, inhibitor development, and infusion-related reactions. It is important for patients to discuss these potential side effects with their healthcare provider to make an informed decision.

What prior FDA approvals exist?

The FDA has approved several treatments for Hemophilia B that involve recombinant technology to replace or enhance Factor IX activity. Notably, recombinant factor IX-albumin fusion protein (rFIX-FP; Idelvion) and glyco-PEGylated recombinant factor IX (rFIX-GP; Rebinyn) have been approved for prophylaxis and treatment of bleeding. These treatments prolong the half-life of Factor IX, providing extended protection against bleeding episodes. While these treatments do not involve gene therapy, they represent significant advancements in managing Hemophilia B by enhancing the stability and activity of Factor IX.

What other types of research exist?

Promising alternatives to PF-06838435 for Hemophilia B treatment include recombinant fusion proteins such as rIX-FP (a fusion of coagulation factor IX with albumin) and glycoPEGylated recombinant factor IX (N9-GP). These therapies have demonstrated prolonged half-life and preserved enzymatic properties, offering effective prophylaxis with potentially fewer injections.

← Back to Search

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

Select...

My hemophilia B is severe with Factor IX activity at 2% or less.

Select...

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:

Select...

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.

Select...

I have active hepatitis B or C.

Select...

I have or had an inhibitor to Factor IX.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ maximum up to 6 years (week 312) after pf-06838435 infusion

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

0 / 7Eligibility criteria met

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.