Gene Transfer Study in Patients With Late Onset Pompe Disease

Open to people ages 18-80

• Subject is aged ≥ 18 years (ambulatory or nonambulatory).
• Subject has a documented clinical diagnosis of Pompe disease by genetic testing.
• Subject has received enzyme replacement therapy (ERT) with rhGAA for the previous ≥ 2 years.
• Subject has been on a stable standard dose (at least 20 mg/kg every 2 weeks) of ERT with rhGAA for at least the previous 6 months.
• Subject has upright FVC ≥ 30% of predicted normal value.
• Subject or legally authorized representative(s) (LAR) (if applicable) provides written informed consent.
• Subject must agree to use appropriate contraception following consent through 6 months post AT845 administration.

• Subject is currently participating in an interventional study or has received gene or cell therapy.
• Subject tests positive for AAV8 neutralizing antibodies with titers above protocol specified threshold.
• Subject has received immune-modulating agents within 90 days before dosing (use of inhaled corticosteroids is allowed).
• Subject tests positive for GAA total antibodies with titers above protocol specified threshold.
• Subject has a high risk for a severe allergic reaction to rhGAA (ie, previous moderate to severe anaphylactic reaction to alglucosidase alfa or and/or a history of sustained high immunoglobulin G [IgG] antibody titers to alglucosidase alfa that in the opinion of the Investigator suggests a high risk for an allergic reaction to ERT).
• Subject has an active viral infection based on clinical observation.
• Subject has a history of, or currently has, a clinically important cardiac condition, such as an echocardiogram (ECHO) with ejection fraction below 40%, or has symptoms or signs of cardiomyopathy that in the opinion of the Investigator precludes enrollment.
• Subject has a clinically significant underlying liver disease.
• Subject has a contraindication to study drug or ingredients or to corticosteroids.