Currently, hemophilia A patients are managed with prophylactic or on-demand replacement therapy with recombinant FVIII or alternative therapeutics. The major challenges of current treatment regimens, such as the short half-life of hemophilia therapeutics with the need for frequent IV injections, encourage the current efforts for gene transfer therapy.

This study will evaluate the safety and preliminary efficacy of ASC618, an AAV vector encoding B-domain deleted codon-optimized human factor VIII under a synthetic liver-directed promoter

Inclusion Criteria:

• Male ≥18 years of age
• Severe or moderately severe hemophilia A (FVIII activity ≤ 2 IU/dL) as evidenced by
• medical history
• Received FVIII prophylactic or on-demand replacement therapy for ≥ 150 accumulated
• days (exposure days)
• ≥12 bleeding episodes if receiving on-demand therapy over the preceding 12 months
• BMI ≤ 30
• Agree to use double-barrier contraceptive until at least 3 consecutive semen samples are negative after ASC-618 infusion

Exclusion Criteria:

• Pre-existing immunity to AAV8 vector as defined by AAV8 total antibodies and neutralizing antibodies qualified tests.
• Current inhibitors, or history of high titer FVIII inhibitors
• Presence of > Grade 2 liver fibrosis on elastography/Fibroscan or comparable imaging methodology
• History of chronic renal disease
• Active infection or any immunosuppressive disorder
• History of cardiac surgery and need anticoagulant therapy
• Any cardiovascular / genetic risk factors for thromboembolic disorders
• Evidence of active Hepatitis B, Hepatitis C, Human Immunodeficiency Virus (HIV)-1/2 or syphilis infection.
• Receipt of any vector or gene transfer agent
• Current antiviral therapy for hepatitis B or C