Study of Long-Term Safety and Efficacy on Gene Therapy in Glycogen Storage Disease Type Ia

NCT03970278 | Completed Results FDA Drug

• 3 other identifiers: 401GSDIA022018-004473-272023-504004-29-00
• Study Type: observational
• Target: 12
• Locations: 4 countries
• Sites: 6

Brief Summary

The primary objective of this study is to determine the long-term safety of DTX401 following a single intravenous (IV) dose in adults with GSDIa.

Conditions

Glycogen Storage Disease Type IA; Von Gierke's Disease (GSD Type Ia)

Keywords

AAV; gene therapy; glucose metabolism disorder; carbohydrate metabolism, inborn errors; genetic diseases; Inborn Metabolic Diseases

Outcome Measures

Primary Outcomes (1)

• Number of Participants With Treatment Emergent Adverse Events (TEAEs), Serious TEAEs and Discontinuations Due to TEAEs

  An adverse event (AE) is defined as any untoward medical occurrence, regardless of its causal relationship to study product. A TEAE is defined as any AE not present prior to the initiation of the drug treatment or any AE already present that worsens in either intensity or frequency following exposure to the drug treatment. A serious TEAE is an AE that meets any of the following criteria in the view of either the Investigator or Ultragenyx: death; life-threatening; inpatient hospitalization or prolongation of existing hospitalization; disability/Incapacity; congenital anomaly/birth defect not present at screening; other important medical events. Severity of events were graded as mild (grade 1), moderate (grade 2), severe (grade 3), life-threatening (grade 4), or death (grade 5). As DTX401 was administered as part of Study 401GSDIA01, all AEs in Study 401GSDIA02 were considered TEAEs.

  From Baseline (Week 52 of 401GSDIA01/Visit 1 of 401GSDIA02) Up to Week 329

Secondary Outcomes (1)

• Change From Baseline in Time to First Hypoglycemic Event During a Controlled Fasting Challenge Over Time

  Baseline (Week 0 of 401GSDIA01), Weeks 52 (Visit 1 of 401GSDIA02), 78, 104, 130, 156, 182, 208, 234, 260, Last Visit (Up to Week 329)

Study Arms (4)

DTX401 Cohort 1

Participants received a single intravenous (IV) dose of 2.0 × 10\^12 GC/kg DTX401(pariglasgene brecaparvovec) with a reactive steroid regimen during their participation in study 401GSDIA01 (NCT03517085). No intervention was provided during the 401GSDIA02 long term follow up study.

Other: No intervention

DTX401 Cohort 2

Participants received a single IV dose of 6.0 × 10\^12 GC/kg DTX401(pariglasgene brecaparvovec) with a reactive steroid regimen during their participation in study 401GSDIA01 (NCT03517085). No intervention was provided during the 401GSDIA02 long term follow up study.

Other: No intervention

DTX401 Cohort 3

Participants received a single IV dose of 6.0 × 10\^12 GC/kg DTX401(pariglasgene brecaparvovec) with an optimized reactive steroid regimen during their participation in study 401GSDIA01 (NCT03517085). No intervention was provided during the 401GSDIA02 long term follow up study.

Other: No intervention

DTX401 Cohort 4

Participants received a single IV dose of 6.0 × 10\^12 GC/kg DTX401(pariglasgene brecaparvovec) with a prophylactic steroid regimen during their participation in study 401GSDIA01 (NCT03517085). No intervention was provided during the 401GSDIA02 long term follow up study.

Other: No intervention

Interventions

No intervention OTHER

No intervention

DTX401 Cohort 1; DTX401 Cohort 2; DTX401 Cohort 3; DTX401 Cohort 4

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Subjects 18 years of age or older with GSDIa previously enrolled in 401GSDIA01.

You may qualify if:

• Received DTX401 in study 401GSDIA01.
• Willing and able to provide written informed consent after the nature of the study has been explained, and prior to any research-related procedures being performed.
• Willing and able to comply with all scheduled study visits, procedures, and requirements.

You may not qualify if:

• Planned or current participation in any other interventional clinical study that may confound the safety or efficacy evaluation of DTX401 during this study.
• Presence or history of any condition that, in the view of the Investigator, poses a risk to subject safety or places the subject at high risk of poor compliance or not completing the study or that would significantly affect the interpretation of study results.

Sponsors & Collaborators

• Ultragenyx Pharmaceutical Inc: lead

Study Sites (6)

UCONN Health

Farmington, Connecticut, 06030-3213, United States

Location

Michigan Medicine University of Michigan

Ann Arbor, Michigan, 48109, United States

Location

University of Texas Health Science Center at Houston

Houston, Texas, 77030, United States

Location

Montreal Children Hospital, McGill University Health Centre

Montreal, Quebec, H4A3J1, Canada

Location

University Medical Center Groningen

Groningen, 9700RB, Netherlands

Location

Complejo Hospitalario Universitario de Santiago

Santiago de Compostela, A Coruna, 15706, Spain

Location

Related Links

• Ultragenyx Transparency Commitment

Biospecimen

Retention: SAMPLES WITH DNA

Blood

MeSH Terms

Conditions

Hepatorenal form of glycogen storage disease; Glycogen Storage Disease Type I; Glucose Metabolism Disorders; Carbohydrate Metabolism, Inborn Errors; Genetic Diseases, Inborn

Condition Hierarchy (Ancestors)

Glycogen Storage Disease; Metabolism, Inborn Errors; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Metabolic Diseases; Nutritional and Metabolic Diseases

Results Point of Contact

• Title: Medical Information
• Organization: Ultragenyx Pharmaceutical Inc

medinfo@ultragenyx.com

1-888-756-8657

Study Officials

• Medical Director

  Ultragenyx Pharmaceutical Inc

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: GT60
• Restrictive Agreement: Yes

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 29, 2019
• First Posted: May 31, 2019
• Study Start: July 15, 2019
• Primary Completion: February 25, 2025
• Study Completion: February 25, 2025
• Last Updated: March 18, 2026
• Results First Posted: March 18, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (3); ES (1); CA (1); NL (1)