Factor VIII Gene Therapy Study in Patients With Hemophilia A

Inclusion Criteria:

- Males age 18 years or older

- Confirmed diagnosis of hemophilia A as evidenced by their medical history with plasma
FVIII activity levels < 1% of normal or at screening.

- Have >150 exposure days (EDs) to FVIII concentrates (recombinant or plasma-derived).

If on prophylaxis, should be able and willing to stop prophylactic treatment at specified
time points throughout the study or If on-demand: should have had > 4 bleeding events in
the last 52 weeks

- Agree to use reliable barrier contraception

Exclusion Criteria:

- History of allergic reaction to any FVIII product

- Current evidence of measurable inhibitor against factor VIII, as assessed by the
central laboratory and/or prior history of inhibitors to FVIII protein

- Evidence of active hepatitis B or C

- Currently on antiviral therapy for hepatitis B or C

- Significant underlying liver disease

- Serological evidence of HIV-1 or HIV-2 with CD4 counts ≤200/mm*3; HIV+ and stable
participants with CD4 count >200/mm*3 and undetectable viral load are eligible to
enroll

- Detectable antibodies reactive with AAVhu37capsid

- Participant with another bleeding disorder that is different from hemophilia A (e.g.,
von Willebrand disease, hemophilia B)

- Participated in a gene transfer trial within the last 52 weeks or in a clinical trial
with an investigational product within the last 12 weeks