Dose-finding Study of SPK-8016 Gene Therapy in Patients With Hemophilia A to Support Evaluation in Individuals With FVIII Inhibitors

Inclusion Criteria for Part 1:

1. Be male and ≥18 years of age;

2. Have clinically severe hemophilia A, defined as:

1. <1% (<1 IU/dL) endogenous FVIII activity levels as historically documented by a
certified laboratory or screening data results; OR

2. 1-2% (1-2 IU/dL) endogenous FVIII activity levels and > 10 bleeding events per
year (in the last 52 weeks prior to screening); OR

3. 1-2% (1-2 IU/dL) endogenous FVIII activity levels and on prophylaxis;

3. Have had >150 exposure days (EDs) to any recombinant and/or plasma-derived FVIII
concentrates or cryoprecipitates

4. Have no prior history of hypersensitivity or anaphylaxis associated with any FVIII or
IV immunoglobulin administration

5. Have no measurable inhibitor against FVIII as assessed by central laboratory, have no
confirmed history of clinically significant FVIII inhibitor, and no clinical signs or
symptoms of decreased response to FVIII administration (Note: family history of
inhibitors will not exclude study participation)

6. Agree to use reliable barrier contraception after the administration of SPK-8016 until
notified by the Investigator.

Exclusion Criteria for Part 1:

1. Have active hepatitis B or C

2. Have significant underlying liver disease.

3. Have serological evidence of HIV-1 or HIV-2 with CD4 counts ≤200/mm3. Participants who
are HIV-positive and stable, with an adequate CD4 count (>200/mm3) and undetectable
viral load, and are on an antiretroviral drug regimen are eligible to enroll

4. Have detectable antibodies reactive with AAV-Spark capsid

5. Have history of chronic infection or other chronic disease

6. Have been dosed in a previous gene therapy research trial within the last 52 weeks or
with an investigational drug within the last 12 weeks

7. Any concurrent clinically significant major disease (such as liver abnormalities or
type I diabetes) or other condition that, in the opinion of the Investigator and/or
Sponsor, makes the subject unsuitable for participation in the study;

8. Unable or unwilling to comply with the schedule of visits and study assessments
described in the clinical protocol.