A Gene Transfer Study for Hemophilia A

Hemophilia A is a condition in which blood is unable to clot effectively. It is caused by a mutation or deletion in the gene that is responsible for producing blood-clotting factor VIII protein. Individuals with hemophilia A suffer from repeated bleeding episodes, often into the joints, which can cause chronic joint disease and sometime results in death due to the inability of the blood to clot efficiently. This chronic joint disease can have significant physical, psychosocial, and quality-of-life effects, including financial burden. The current standard of care includes the use of factor-based therapies which are given either as prophylaxis or to treat bleeding, as well as new non-factor prophylaxis therapies.

Inclusion criteria

• Males age 18 years or older
• Confirmed diagnosis of hemophilia A as evidenced by their medical history with baseline FVIII activity levels <=2%
• Have received >150 exposure days (EDs) to FVIII concentrates or cryoprecipitate
• Have no prior history of allergic reaction to any FVIII product
• Have no measurable inhibitor against FVIII as assessed by the central laboratory and have no prior history of inhibitors to FVIII protein and no clinical signs or symptoms of decreased response to FVIII administration
• Agree to use reliable barrier contraception

Exclusion criteria

• Evidence of active hepatitis B or C
• Currently on antiviral therapy for hepatitis B or C
• Have significant underlying liver disease
• Have serological evidence* of HIV-1 or HIV-2 with CD4 counts ≤200/mm3 and who are on an antiretroviral drug regimen (* participants who are HIV+ and stable with CD4 count >200/mm3 and undetectable viral load are eligible to enroll)
• Have detectable antibodies reactive with AAV-Spark200 capsid
• 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