Safety and Dose-Finding Study of DTX401 (AAV8G6PC) in Adults With Glycogen Storage Disease Type Ia (GSDIa)

Inclusion Criteria:

- Males and females ≥18 years of age

- Documented GSDIa with confirmation by molecular testing

- Documented history of ≥1 hypoglycemic event with blood glucose <60 mg/dL (<3.33
mmol/L)

- Patient's GSDIa disease is stable as evidenced by no hospitalization for severe
hypoglycemia during the 4-week period preceding the screening visit

Exclusion Criteria:

- Anti-AAV8 neutralizing antibody titer ≥1:5

- Screening or Baseline (Day 0) blood glucose level <60 mg/dL (<3.33 mmol/L)

- Liver transplant, including hepatocyte cell therapy/transplant

- Presence of liver adenoma >5 cm in size

- Presence of liver adenoma >3 cm and ≤5 cm in size that has a documented annual growth
rate of ≥0.5 cm per year

- Significant hepatic inflammation or cirrhosis as evidenced by imaging or any of the
following laboratory abnormalities: alanine aminotransferase (ALT) or aspartate
aminotransferase (AST) > upper limit of normal (ULN), total bilirubin >1.5 × ULN,
alkaline phosphatase >2.5 × ULN

Note additional inclusion/exclusion criteria may apply, per protocol.