NCT03861273

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

Phase 3, Open-label, Single-arm Study to Evaluate Efficacy and Safety of FIX Gene Transfer With PF-06838435 (rAAV-Spark100-hFIX-R338L) in Adult Male Participants With Moderately Severe to Severe Hemophilia B (FIX:C ≤2%) (BeneGene-2)

• Status: Active Not Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 51 (actual)
• Sponsor: Pfizer · Industry
• Sex: Male
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

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 circulating activity of 2% or less). The gene therapy is designed to introduce genetic material into cells to compensate for missing or non-functioning Factor IX. Eligible study participants will have completed a minimum 6 months of routine Factor IX prophylaxis therapy during the lead in study (C0371004). Participants will be dosed once (intravenously) and will be evaluated over the course of 6 years. The main objective of the study will evaluate the annualized bleeding rate \[ABR\] for participants treated with gene therapy versus standard of care (SOC) therapy (FIX prophylaxis replacement regimen).

Conditions

• Hemophilia B

Interventions

Type	Name	Description
BIOLOGICAL	PF-06838435/ fidanacogene elaparvovec	Gene Therapy

Timeline

• Start date: 2019-07-29
• Primary completion: 2022-11-16
• Completion: 2031-02-25
• First posted: 2019-03-04
• Last updated: 2026-04-03
• Results posted: 2024-03-27

Locations

65 sites across 16 countries: United States, Australia, Brazil, Canada, France, Germany, Greece, Italy, Japan, Saudi Arabia, South Korea, Spain, Sweden, Taiwan, Turkey (Türkiye), United Kingdom

Regulatory

• FDA-regulated drug study