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

Brief Title

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

Official Title

A Phase 1/2, Open-Label Safety and Dose-Finding Study of Adeno-Associated Virus (AAV) Serotype 8 (AAV8)-Mediated Gene Transfer of Glucose-6- Phosphatase (G6Pase) in Adults With Glycogen Storage Disease Type Ia (GSDIa)

Brief Summary

      The primary objective of the study is to determine the safety of single doses of DTX401,
      including the incidence of dose-limiting toxicities (DLTs) at each dose level.

Detailed Description

      Subjects enrolled in the 401GSDIA01 study will be monitored for 52 weeks following DTX401
      administration. Subjects in Cohorts 1, 2, and 3 will receive reactive oral steroid treatment
      for possible vector-induced hepatitis following treatment with DTX401. Subjects in Cohort 4
      will receive prophylactic oral steroid treatment to prevent possible vector-induced
      hepatitis. After completion of the Week 52 visit or early withdrawal, subjects will be
      offered enrollment into a 4-year extension study.

Study Phase

Phase 1/Phase 2

Study Type


Primary Outcome

Adverse Events (AEs), Treatment-emergent Adverse Events (TEAEs), and Serious Adverse Events (SAEs)

Secondary Outcome

 Change from Baseline in Time (Minutes) to First Hypoglycemic Event During a Controlled Fasting Challenge at Weeks 12, 24, and 52





Study Arms / Comparison Groups

 DTX401 Dose 1
Description:  DTX401 solution for intravenous (IV) infusion


* Includes publications given by the data provider as well as publications identified by National Clinical Trials Identifier (NCT ID) in Medline.

Recruitment Information

Recruitment Status


Estimated Enrollment


Start Date

July 24, 2018

Completion Date

December 2021

Primary Completion Date

December 2021

Eligibility Criteria

        Key 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

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

        Key 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.




18 Years - N/A

Accepts Healthy Volunteers



Medical Director, , 

Location Countries


Location Countries


Administrative Informations



Organization ID


Secondary IDs


Responsible Party


Study Sponsor

Ultragenyx Pharmaceutical Inc

Study Sponsor

Medical Director, Study Director, Ultragenyx Pharmaceutical Inc

Verification Date

April 2021