NCT05139316

A Study of Adeno-Associated Virus Serotype 8-Mediated Gene Transfer of Glucose-6-Phosphatase in Patients With Glycogen Storage Disease Type Ia (GSDIa)

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of Adeno-Associated Virus Serotype 8-Mediated Gene Transfer of Glucose-6-Phosphatase in Patients With Glycogen Storage Disease Type Ia

• Status: Completed
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 49 (actual)
• Sponsor: Ultragenyx Pharmaceutical Inc · Industry
• Sex: All
• Age: 8 Years
• Healthy volunteers: Not accepted

Summary

The primary objectives of this study are to evaluate the efficacy of DTX401 to reduce or eliminate dependence on exogenous glucose replacement therapy to maintain euglycemia and to maintain or improve the quality of glucose control.

Detailed description

Study DTX401-CL301 is a phase 3 study to determine the efficacy and confirm the safety of DTX401 in patients 8 years and older with glycogen storage disease type Ia (GSDIa). Participants will be randomized 1:1 to DTX401 or placebo group, and followed closely for 48 weeks. At week 48 eligible participants will cross over and receive DTX401 if they had previously received placebo or placebo if they had previously received DTX401, and will be followed closely for an additional 96 weeks. After completion of week 144 or early withdrawal, participants will be offered enrollment into a Disease Monitoring Program (DMP) where they will be followed for at least 10 years post DTX401 infusion. In Japan, there will be a single open label study arm and all participants will be treated with DTX401. At week 48, Japanese participants will be offered enrollment into a Disease Monitoring Program (DMP) where they will be followed for at least 10 years post DTX401 infusion.

Conditions

• Glycogen Storage Disease Type IA

Interventions

Type	Name	Description
GENETIC	DTX401	nonreplicating, recombinant, adeno-associated virus (AAV) serotype 8 (AAV8)
OTHER	Placebo	Normal Saline infusion
DRUG	Oral prednisolone	Participants who receive DTX401 solution will receive oral prednisolone
DRUG	Placebo for oral prednisolone	Participants who receive placebo will receive placebo oral prednisolone to maintain the study blind

Timeline

• Start date: 2021-11-08
• Primary completion: 2024-02-20
• Completion: 2026-02-20
• First posted: 2021-12-01
• Last updated: 2026-03-25

Locations

20 sites across 9 countries: United States, Brazil, Canada, Denmark, Germany, Italy, Japan, Netherlands, Spain

Regulatory

• FDA-regulated drug study