A Phase 3 interventional study of DTX401 and Placebo in Glycogen Storage Disease Type IA, sponsored by Ultragenyx Pharmaceutical Inc. Completed at 20 sites in 9 countries. Open to participants aged 8 Years and older. Per ClinicalTrials.gov, last updated 2026-03-25.
Sponsored by Ultragenyx Pharmaceutical Inc · Phase 3, Interventional, and Treatment
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.
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.
Key Inclusion Criteria:
Key Exclusion Criteria:
Note: additional inclusion/exclusion criteria may apply, per protocol
Participants receive single peripheral intravenous (IV) infusion of DTX401 in solution. At week 48 participants receive single peripheral IV infusion of Placebo.
Genetic: DTX401 · Other: Placebo · Drug: Oral prednisolone · Drug: Placebo for oral prednisolone
Participants receive single peripheral IV infusion of Placebo. At week 48 eligible participants receive single peripheral IV infusion of DTX401 solution.
Genetic: DTX401 · Other: Placebo · Drug: Oral prednisolone · Drug: Placebo for oral prednisolone
Participants receive single peripheral intravenous (IV)infusion of DTX401 in solution.
Genetic: DTX401 · Drug: Oral prednisolone
nonreplicating, recombinant, adeno-associated virus (AAV) serotype 8 (AAV8)
Also known as: pariglasgene brecaparvovec
Normal Saline infusion
Participants who receive DTX401 solution will receive oral prednisolone
Participants who receive placebo will receive placebo oral prednisolone to maintain the study blind
Percent Change from Baseline to Week 48 in Daily Cornstarch Intake
Time frame: Baseline, Week 48
Change from Baseline to Week 48 in Number of Total Daily Doses of Cornstarch in DTX401 Group Compared to Placebo Group
Time frame: Baseline, Week 48
Change from Baseline to Week 48 in Percentage of Glucose Values in Hypoglycemic Range (<70mg/dL [3.9 mmol/L])
Time frame: Baseline, Week 48
Patient Global Impression of Change (PGIC) Assessment Score at Week 48
Time frame: Baseline, Week 48
Change from Baseline to Week 48 in Time to Hypoglycemia (<54 mg/dL [3.0 mmol/L]) During a Controlled Fasting Challenge
Time frame: Baseline, Week 48
Change from Baseline to Week 48 in Percentage of Glucose Values in the Range of 70-120 mg/dL (3.9-6.7 mmol/L)
Time frame: Baseline, Week 48
Number of Treatment Emergent Adverse Events (TEAEs), TEAEs of Special Interest, Serious TEAEs, Related TEAEs, Discontinuations From Study or Investigational Product Due to Adverse Events (AEs), and Fatal AEs
Time frame: up to 144 weeks
Plan to share: No
This study is completed, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Hepatorenal form of glycogen storage disease
Ultragenyx Pharmaceutical Inc