For Healthcare Professionals

Study to Evaluate the Efficacy and Safety of PF-07055480 / Giroctocogene Fitelparvovec Gene Therapy in Moderately Severe to Severe Hemophilia A Adults


About the study

C3731003 is a pivotal Phase 3 study to evaluate the clinical efficacy and safety of a single IV infusion of PF-07055480 / giroctocogene fitelparvovec (Recombinant AAV2/6 Human Factor VIII Gene Therapy) in adult male participants with moderately severe or severe hemophilia A (FVIII:C≤1%) for the study duration of 5 years. The study will enroll eligible participants who have been followed on routine prophylaxis with FVIII products in the Lead-In study C0371004.

Who can take part

You may be eligible to participate in the study if you meet the following criteria:


Main inclusion Criteria

  1. Males who have been followed on routine Factor VIII prophylaxis therapy during the lead-in study (C0371004) and have > = 150 documented exposure days to a Factor VIII protein product
  2. Moderately severe to severe hemophilia A (Factor VIII activity < =1%)
  3. Suspension of FVIII prophylaxis therapy post study drug infusion


Main exclusion Criteria

  1. Anti-AAV6 neutralizing antibodies
  2. History of inhibitor to Factor VIII
  3. Laboratory values at screening visit that are abnormal or outside acceptable study limits
  4. Significant and/or unstable liver disease, biliary disease, significant liver fibrosis
  5. Conditions associated with increased thromboembolic risk such as inherited or acquired thrombophilia, or a history of thrombotic events
  6. Planned surgical procedure requiring Factor VIII surgical prophylactic factor treatment 12 months from screening visit
  7. Active hepatitis B or C
  8. Serological evidence of human immunodeficiency virus HIV-1 or HIV-2 with Cluster of Differentiation 4 positive (CD4+) cell count ≤200 mm3 and/or viral load >20 copies/mL

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Study Locations

Enter your ZIP code/Postal code/PIN code to locate study sites near you:

How to Apply

Contact the study center to learn if this study is a good match for you.

Study’s details


Hemophilia A

Age (in years)

18 - 64


Phase 3

Participants needed


Est. Completion Date

Sep 28, 2028

Treatment type



Pfizer identifier


Study number


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