Long Term Follow Up to Evaluate DTX301 in Adults With Late-Onset OTC Deficiency

Active, not recruiting

• Conditions: Ornithine Transcarbamylase (OTC) Deficiency

• Registration Number: NCT03636438
• Lead Sponsor: Ultragenyx Pharmaceutical Inc

Brief Summary

Determine the long-term safety of DTX301 following a single intravenous (IV) dose in adults with late-onset ornithine transcarbamylase (OTC) deficiency.

Detailed Description

Study 301OTC02 is a long-term follow-up study to evaluate the safety and efficacy of adeno-associated virus (AAV) serotype 8 (AAV8)-mediated gene transfer of human OTC in adults with late-onset OTC deficiency. Only subjects who complete Study 301OTC01 (NCT02991144) are eligible to participate in Study 301OTC02.

Study Timeline

• Study First Submitted: 2018-08-15
• Study First Submitted QC: 2018-08-15
• Study First Posted: 2018-08-17
• Study Start: 2018-08-30
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-29
• Last Update Posted: 2025-05-02
• Primary Completion: 2029-12
• Study Completion: 2029-12

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 11

Inclusion Criteria

1. Completed the Week 52 visit in Study 301OTC01.
2. Willing and able to provide written informed consent.
3. Willing, able, and committed to comply with scheduled study site visits, study procedures, and requirements.

Exclusion Criteria

1. Planned or current participation in another interventional clinical study that may confound the efficacy or safety evaluation of DTX301 during the duration of this study.
2. Any clinically significant medical condition that, in the opinion of the investigator, would pose a risk to subject safety or would impede the study.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Number of Participants with Adverse Events and Serious Adverse Events	Up to 416 weeks

Secondary Outcome Measures

Name	Time	Method
Change from Baseline Over Time in 24-Hour Area Under the Curve for Plasma Ammonia	Baseline (Day 0 of Study 301OTC01) up to 208 weeks following DTX301 administration
Change from Baseline Over Time in the Ureagenesis Rate	Baseline (average of Screening and Day 1) up to 416 weeks following DTX301 administration	Sodium acetate is used as a tracer to measure the rate of ureagenesis

Trial Locations

Locations (9)

Boston Children's Hospital; 🇺🇸 Boston, Massachusetts, United States

University Hospital Cleveland Medical Center/Case Western Reserve University; 🇺🇸 Cleveland, Ohio, United States

Queen Elizabeth Hospital, Department of Endocrinology; 🇬🇧 Birmingham, United Kingdom

Alberta Children's Hospital; 🇨🇦 Calgary, Alberta, Canada

Hopital Femme Mere Enfant; 🇫🇷 Bron, Rhone, France

Hospital Universitario de Cruces. Servicio de Pediatria; 🇪🇸 Barakaldo, Vizcaya, Spain

Icahn School of Medicine; 🇺🇸 New York, New York, United States

Hospital Clinico Universitario de Santiago; 🇪🇸 Santiago De Compostela, Coruna, Spain

The Children's Hospital Colorado; 🇺🇸 Aurora, Colorado, United States