Status:

ACTIVE_NOT_RECRUITING

A Study to Evaluate the Efficacy and Safety of Factor IX Gene Therapy With PF-06838435 in Adult Males With Moderately Severe to Severe Hemophilia B

Lead Sponsor:

Pfizer

Conditions:

Hemophilia B

Eligibility:

MALE

18-65 years

Phase:

PHASE3

Brief Summary

This study will evaluate the efficacy and safety of PF-06838435 (a gene therapy drug) in adult male participants with moderately severe to severe hemophilia B (participants that have a Factor IX circu...

Eligibility Criteria

Inclusion

  • Inclusion Criteria
  • Males who completed 6 months of Factor IX prophylaxis therapy during the lead-in study (C0371004) prior to providing consent at the screening visit for this study.
  • Documented moderately severe to severe hemophilia B (Factor IX activity \< =2%)
  • Previous experience with FIX therapy (=\>50 documented exposure days to a FIX protein product)
  • Suspension of prophylaxis therapy for hemophilia B after administration of the study drug
  • Laboratory values (hemoglobin, platelets and creatinine) within study specified limits
  • Agree to contraception until components of the drug are eliminated from their body
  • Capable of giving signed informed consent
  • Exclusion Criteria
  • Anti-AAVRh74var neutralizing antibodies (nAb) titer above the established threshold (ie, positive for nAb).
  • History of inhibitor to Factor IX or inhibitor detected during screening. Clinical signs or symptoms of decreased response to Factor IX
  • Hypersensitivity to Factor IX replacement product or IV immunoglobulin administration
  • History of chronic infection or other chronic disease
  • Any conditions associated with increased thromboembolic risk
  • Concurrent clinically significant major disease or condition unsuitable for participation and/or may interfere with the interpretation of study results
  • Laboratory values at screening visit that are abnormal or outside acceptable study limits
  • Current unstable liver or biliary disease
  • Currently on antiviral therapy for hepatitis B or C
  • Planned surgical procedure requiring Factor IX surgical prophylactic factor treatment 15 months from screening visit
  • Use of restricted therapies (e.g., blood products, acetylsalicylic acid \[aspirin\] or ibuprofen, other investigational therapy, and by-passing agents)
  • Previously dosed in a gene therapy research trial at any time or in an interventional clinical study within 12 weeks of screening visit
  • Active hepatitis B or C; hepatitis B surface antigen, hepatitis B virus deoxyribonucleic acid positivity, or hepatitis C virus ribonucleic acid positivity
  • Significant liver disease
  • Serological evidence of HIV1 or HIV2 infection with either CD4+ cell count \<=200 mm3 and/or a viral load \>20 copies/mL
  • Study and sponsor staff involved in the conduct of the study and their families
  • Unable to comply with study procedures
  • Sensitivity to heparin or heparin induced thrombocytopenia
  • Sensitivity to any of the study interventions, or components thereof, or drug or other allergy

Exclusion

    Key Trial Info

    Start Date :

    July 29 2019

    Trial Type :

    INTERVENTIONAL

    Allocation :

    ACTUAL

    End Date :

    February 25 2031

    Estimated Enrollment :

    51 Patients enrolled

    Trial Details

    Trial ID

    NCT03861273

    Start Date

    July 29 2019

    End Date

    February 25 2031

    Last Update

    September 30 2025

    Active Locations (60)

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    Page 1 of 15 (60 locations)

    1

    University of California, San Francisco - Clinical Research Center

    San Francisco, California, United States, 94143

    2

    University of California, San Francisco - Outpatient Hematology Clinic

    San Francisco, California, United States, 94143

    3

    Hemophilia and Thrombosis Center at the University of Colorado Anschutz Medical Campus

    Aurora, Colorado, United States, 80045

    4

    Indiana Hemophilia & Thrombosis Center, Inc.

    Indianapolis, Indiana, United States, 46260