A clinical study to learn about the effects of a virus that transfers the gene for human Ornithine Transcarbamylase (OTC) in adults with late-onset OTC deficiency in the long term

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 Ornithine Transcarbamylase (OTC) in Adults with Late-Onset OTC Deficiency

Status

Not yet recruiting

Phases

Phase 1Phase 2

Study type

Interventional

Source

EU CTR

Registry ID

EUCTR2018-000156-18-GB

Enrollment

Registered

2018-05-02

Start date

2018-08-15

Completion date

Unknown

Last updated

2020-07-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Ornithine transcarbamylase deficiency MedDRA version: 20.0 Level: LLT Classification code 10071107 Term: Ornithine transcarbamylase deficiency System Organ Class: 100000004850

Interventions

Product Name: DTX301 Pharmaceutical Form: Concentrate for solution for infusion INN or Proposed INN: Not yet assigned Other descriptive name: DTX301 Concentration unit: Other Concentration type: not l

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Completed the Week 52 visit in Study 301OTC01. Note that the Day 0 visit of Study 301OTC02 may coincide with the Week 52 visit of 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. Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range 18 F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range 1

Exclusion criteria

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.

Design outcomes

Primary

Measure	Time frame
Main Objective: To determine the long-term safety of DTX301 following a single IV dose in adults with late-onset OTC deficiency.;Secondary Objective: To evaluate the long-term efficacy of DTX301 on AUC0-24 for plasma ammonia following a single IV dose in adults with late-onset OTC deficiency. To evaluate the long-term effects of DTX301 on the rate of ureagenesis in adults with late-onset OTC deficiency.;Primary end point(s): The incidence of AEs and SAEs for each dosing cohort assessed by severity and relationship to study product.;Timepoint(s) of evaluation of this end point: From the time the subject signs the Informed Consent Form through the end of study/early withdrawal visit.	—

Measure

Time frame

Main Objective: To determine the long-term safety of DTX301 following a single IV dose in adults with late-onset OTC deficiency.;Secondary Objective: To evaluate the long-term efficacy of DTX301 on AUC0-24 for plasma ammonia following a single IV dose in adults with late-onset OTC deficiency. To evaluate the long-term effects of DTX301 on the rate of ureagenesis in adults with late-onset OTC deficiency.;Primary end point(s): The incidence of AEs and SAEs for each dosing cohort assessed by severity and relationship to study product.;Timepoint(s) of evaluation of this end point: From the time the subject signs the Informed Consent Form through the end of study/early withdrawal visit.

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Secondary

Measure	Time frame
Secondary end point(s): The change from baseline (Day 0 of Study 301OTC01) in AUC 0-24 for plasma ammonia over time to 260 weeks following IV administration of DTX301. The change from baseline (baseline of each subject before DTX301 administration in study 301OTC01) in the rate of ureagenesis (as measured by the generation of [13C] urea over 4 hours) as determined by gas chromatography mass spectrometry over time to 260 weeks following IV administration of DTX301. ;Timepoint(s) of evaluation of this end point: Plasma ammonia: Day 0, Week 52, Week 104, Week 156, Week 208 Ureagenesis: Day 0, Week 26, Week 52, Week 78, Week 104, Week 130, Week 156, Week 182, Week 208	—

Measure

Time frame

Secondary end point(s): The change from baseline (Day 0 of Study 301OTC01) in AUC 0-24 for plasma ammonia over time to 260 weeks following IV administration of DTX301. The change from baseline (baseline of each subject before DTX301 administration in study 301OTC01) in the rate of ureagenesis (as measured by the generation of [13C] urea over 4 hours) as determined by gas chromatography mass spectrometry over time to 260 weeks following IV administration of DTX301. ;Timepoint(s) of evaluation of this end point: Plasma ammonia: Day 0, Week 52, Week 104, Week 156, Week 208 Ureagenesis: Day 0, Week 26, Week 52, Week 78, Week 104, Week 130, Week 156, Week 182, Week 208

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Countries

Canada, Spain, United Kingdom, United States

Contacts

Public ContactGene Therapy Regulatory Affairs

Ultragenyx Pharmaceutical, Inc.

jrae@ultragenyx.com+16177140705

Outcome results

None listed

Source: EU CTR (via WHO ICTRP) · Data processed: Feb 4, 2026