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A Study of Recombinant AAV2/6 Human Factor 8 Gene Therapy SB-525 (PF-07055480) in Subjects With Severe Hemophilia A

Phase 2
Completed
Conditions
Hemophilia A
Interventions
Biological: SB-525 (PF-07055480)
Registration Number
NCT03061201
Lead Sponsor
Pfizer
Brief Summary

The purpose of the study is to evaluate the safety, tolerability and time-course profile of FVIII activity after dosing with SB-525 (PF-07055480)

Detailed Description

The proposed clinical study uses a recombinant adeno-associated virus 2/6 (AAV2/6) vector encoding the cDNA for the B-domain deleted human F8 (hF8). The secreted FVIII has the same amino acid sequence as approved recombinant anti hemophilic factors (Refacto® and Xyntha®). The SB-525 (PF-07055480) vector encodes a liver-specific promotor module and AAV2/6 exhibits liver tropism, thus providing the potential for long-term hepatic production of FVIII in hemophilia A subjects.

The constant production of FVIII after a single SB-525 (PF-07055480) administration may provide potential benefit in durable protection against bleeding and the complications thereof without lifelong repetitive IV factor replacement administration.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
13
Inclusion Criteria
  • Male ≥18 years of age
  • Severe hemophilia A (past evidence of circulating FVIII activity of < 1% normal)
  • Treated or exposed to FVIII concentrates or cryoprecipitate for at least 150 exposure days
  • ≥12 bleeding episodes if receiving on-demand therapy over the preceding 12 months
  • Agree to use double barrier contraceptive until at least 3 consecutive semen samples are negative for AAV 2/6 after SB-525 infusion
Exclusion Criteria
  • Presence of neutralizing antibodies
  • Current inhibitor, or history of FVIII inhibitor (except for transient low titer inhibitor detected in childhood)
  • History of hypersensitivity response to FVIII
  • History of Hepatitis B or HIV-1/2 infection
  • History of Hepatitis C, unless viral assays in two samples, collected at least 6 months apart, are negative
  • Evidence of any bleeding disorder in addition to hemophilia A
  • Markers of hepatic inflammation or overt or occult cirrhosis
  • History of chronic renal disease or creatinine ≥ 1.5 mg/dL
  • Presence of liver mass on magnetic resonance imaging (MRI), or, positive alpha fetoprotein
  • Presence of > grade 2 liver fibrosis on elastography for subjects with history of treated Hepatitis C or suspicion of chronic liver disease

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Sequential dose escalationSB-525 (PF-07055480)SB-525 (PF-07055480) is administered as a single infusion
Primary Outcome Measures
NameTimeMethod
Changes in circulating FVIII activityUp to 5 years after SB-525 (PF-07055480) infusion
Incidence of adverse events and serious adverse eventsUp to 5 years after SB-525 (PF-07055480) infusion
Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (22)

UPMC Montefiore Clinical and Translational Research Center

🇺🇸

Pittsburgh, Pennsylvania, United States

City of Hope Medical Center

🇺🇸

Duarte, California, United States

Emory University School of Medicine

🇺🇸

Atlanta, Georgia, United States

Hemophilia Center of Western PA

🇺🇸

Pittsburgh, Pennsylvania, United States

UPMC, Investigational Drug Service

🇺🇸

Pittsburgh, Pennsylvania, United States

Washington Institute for Coagulation

🇺🇸

Seattle, Washington, United States

University of California, San Francisco - Investigational Drug Service (IDS) Pharmacy

🇺🇸

San Francisco, California, United States

Vanderbilt Hemostasis-Thrombosis Clinic

🇺🇸

Nashville, Tennessee, United States

University of California, San Francisco - Outpatient Hematology Clinic

🇺🇸

San Francisco, California, United States

University of California, San Francisco -Moffitt Hospital

🇺🇸

San Francisco, California, United States

University Of Miami Hospital and Clinics/Sylvester Comprehensive Cancer Center

🇺🇸

Miami, Florida, United States

Vanderbilt University Medical Center Clinical Research Center

🇺🇸

Nashville, Tennessee, United States

Vanderbilt Hemostasis Treatment Clinic

🇺🇸

Nashville, Tennessee, United States

Arkansas Children's Hospital

🇺🇸

Little Rock, Arkansas, United States

Midtown Ambulatory Care Center

🇺🇸

Sacramento, California, United States

UC Davis Ambulatory Care Clinic

🇺🇸

Sacramento, California, United States

UC Davis Comprehensive Cancer Center

🇺🇸

Sacramento, California, United States

UC Davis CTSC Clinical Research Center

🇺🇸

Sacramento, California, United States

UC Davis Medical Center

🇺🇸

Sacramento, California, United States

USF Health Morsani Center For Advanced Healthcare

🇺🇸

Tampa, Florida, United States

UC Davis Hemophilia Treatment Center

🇺🇸

Sacramento, California, United States

UC Davis Investigational Drug Services Pharmacy

🇺🇸

Sacramento, California, United States

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