Ornithine Transcarbamylase (OTC) DeficiencyPhase 1/2CAPtivateNCT02991144
Safety and Dose-Finding Study of DTX301 (scAAV8OTC) in Adults With Late-Onset Ornithine Transcarbamylase (OTC) Deficiency
A Phase 1/2 study testing scAAV8OTC, Reactive Corticosteroid Taper Regimen and Prophylactic Corticosteroid Taper Regimen in people with Ornithine Transcarbamylase (OTC) Deficiency, run by Ultragenyx Pharmaceutical Inc at 9 sites in 4 countries.
Trial summary
This is a Phase 1/2, open-label, single arm, multicenter, safety and dose finding study of DTX301 in adults with late-onset OTC deficiency. The primary objective of the study is to determine the safety of single intravenous (IV) doses of DTX301. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Ornithine Transcarbamylase (OTC) Deficiency
- What is being tested?
- scAAV8OTC, Reactive Corticosteroid Taper Regimen and Prophylactic Corticosteroid Taper Regimen
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 16 participants
- Where
- 9 sitesin 4 countries
- Study dates
- 31 Jul 2017to 16 Dec 2021
- Phase
- Phase 1/2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Males and females ≥18 years of age with documented diagnosis of late onset (defined as first manifestation of signs and symptoms at ≥1 month of age) OTC deficiency, confirmed via enzymatic, biochemical, or molecular testing
- Documented history of ≥1 symptomatic hyperammonemia event with ammonia ≥100 µmol/L.
- Subject's OTC deficiency is stable as evidenced by either a) no clinical symptoms of hyperammonemia OR b) an ammonia level <100 µmol/L within the 4 week period preceding the Screening visit.
- On ongoing daily stable dose of ammonia scavenger therapy for ≥4 weeks.
- Males and all females of childbearing potential must be willing to use effective contraception at the time of administration of gene transfer and for the 52 weeks following administration of DTX301
Who cannot join
- At Screening or Baseline (Day 0), plasma ammonia level ≥ 100 μmol/L for patients who historically maintain normal ammonia levels; OR plasma ammonia level ≥ 200 μmol/L for patients who historically are not able to fully control ammonia levels with baseline management; OR signs and symptoms of hyperammonemia.
- Liver transplant, including hepatocyte cell therapy/transplant.
- History of liver disease
- Significant hepatic inflammation or cirrhosis
- Serum creatinine >2.0 mg/dL.
- Participation in another investigational medicine study (including another gene transfer trial) within 3 months of Screening
- Pregnant or nursing
- Note additional inclusion/exclusion criteria may apply, per protocol.
Trial locations and contacts
9 sites in 4 countries.
9 sites in 4 countries
United States4 sites
The Children's Hospital Colorado
Aurora, Colorado, 80045
Boston Children's Hospital
Boston, Massachusetts, 02115
University Hospital Cleveland Medical Center/Case Western Reserve University
Cleveland, Ohio, 44106
Icahn School of Medicine at Mount Sinai
New York, New York, 10029-6508
Spain2 sites
Hospital Universitario de Cruzes
Barakaldo, Vizcaya, 48903
Hospital Clinico Universitario de Santiago
Santiago de Compostela, A Coruna, 15706
United Kingdom2 sites
Queen Elizabeth Hospital
Birmingham, B15 2TH
National Hospital for Neurology & Neurosurgery
London, London City, WC1N 3BG
About this study
Official title: A Phase 1/2, Open-Label Safety and Dose-Finding Study of Adeno-Associated Virus (AAV) Serotype 8 (AAV8)-Mediated Gene Transfer of Human Ornithine Transcarbamylase (OTC) in Adults With Late-Onset OTC Deficiency
This is a Phase 1/2, open-label, single arm, multicenter, safety and dose finding study of DTX301 in adults with late-onset OTC deficiency. The primary objective of the study is to determine the safety of single intravenous (IV) doses of DTX301.
Read the detailed description
Eligible participants will receive a single IV infusion of DTX301. Dose escalation will be conducted according to a model that uses the collected data to predict the safety profile of the dose in order to determine the optimal biological dose (OBD). The decision to proceed to the next dose cohort will be made after the data monitoring committee (DMC) has evaluated the safety data for all participants in a dosing cohort. Participants will be followed for 52 weeks after dosing. After completion of this study, participants will be asked to enroll in a 4-year extension study to evaluate the long term (a total of 5 years) safety and efficacy of DTX301.
This study was previously posted by Dimension Therapeutics, which has been acquired by Ultragenyx.
- Being tested
- scAAV8OTC, Reactive Corticosteroid Taper Regimen, Prophylactic Corticosteroid Taper Regimen
- Keywords
- Gene Transfer, OTC Deficiency, Urea Cycle Disorder
- Medical subject headings
- Ornithine Carbamoyltransferase Deficiency Disease, Urea Cycle Disorders, Inborn
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
scAAV8OTCGenetic
Also called DTX301
non-replicating, recombinant scAAV8 encoding human ornithine transcarbamylase (OTC)
Reactive Corticosteroid Taper RegimenDrug
Oral prednisone [or oral prednisolone] 60 mg/day week 1, 40 mg/day Week 2, 30 mg/day Weeks 3 and 4, tapered by 5 mg/week Week 5 and beyond until liver enzymes return to baseline levels.
Corticosteroid treatment will be considered when a participant's alanine aminotransferase (ALT) level exceeded the upper limit of normal (ULN) and the ALT increase was considered by the Investigator to be related to DTX301.
Prophylactic Corticosteroid Taper RegimenDrug
Oral prednisone [or oral prednisolone] 60 mg/day at least 5 days prior to DTX301 administration, tapered over 9 weeks.
A prophylactic corticosteroid taper regimen will be administered to prevent or minimize transient vector-induced hepatic effects.
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1: DTX301 2.0 × 10^12 GC/kg | Experimental | DTX301 (scAAV8OTC) 2.0 × 10^12 GC/kg will be administered as a single peripheral IV infusion. A reactive corticosteroid taper regimen will be administered to control transient vector-induced hepatic effects. Sodium acetate will be used as a tracer to measure the rate of ureagenesis. Receives: Genetic: scAAV8OTC; Drug: Reactive Corticosteroid Taper Regimen |
| Cohort 2: DTX301 6.0 × 10^12 GC/kg | Experimental | DTX301 (scAAV8OTC) 6.0 × 10^12 GC/kg will be administered as a single peripheral IV infusion. A reactive corticosteroid taper regimen will be administered to control transient vector-induced hepatic effects. Sodium acetate will be used as a tracer to measure the rate of ureagenesis. Receives: Genetic: scAAV8OTC; Drug: Reactive Corticosteroid Taper Regimen |
| Cohort 3: DTX301 1.0 × 10^13 GC/kg | Experimental | DTX301 (scAAV8OTC) 1.0 × 10^13 GC/kg will be administered as a single peripheral IV infusion. A reactive corticosteroid taper regimen will be administered to control transient vector-induced hepatic effects. Sodium acetate will be used as a tracer to measure the rate of ureagenesis. Receives: Genetic: scAAV8OTC; Drug: Reactive Corticosteroid Taper Regimen |
| Cohort 4: DTX301 1.0x10^13 GC/kg + Prophylactic Corticosteroids | Experimental | A prophylactic corticosteroid taper regimen (oral prednisone [or prednisolone], 60 mg tapered over 9 weeks) will be administered before dosing with DTX301 (scAAV8OTC) to prevent or minimize transient vector-induced hepatic effects. DTX301 (scAAV8OTC) 1.0x10^13 GC/kg administered as a single peripheral IV infusion. Sodium acetate will be used as a tracer to measure the rate of ureagenesis. Receives: Genetic: scAAV8OTC; Drug: Prophylactic Corticosteroid Taper Regimen |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Adverse Events (AEs), Treatment-Emergent Adverse Events (TEAEs), Serious Adverse Events (SAEs), Deaths, and TEAEs Leading to Discontinuation
AE: any untoward medical occurrence regardless of its causal relationship to study product. TEAE: any event not present before exposure to study product or any event already present that worsens in either intensity or frequency after exposure to study product. SAE: any event that results in death; is immediately life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; results in a congenital anomaly/birth defect; is an important medical event, according to the investigator. AE intensity was rated as Grade 1 (mild), 2 (moderate), 3 (severe), 4 (life threatening), or 5 (death) according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE). The relationship or association of the study product in causing or contributing to the AE was characterized as: unrelated; possible; probably; definite.
Measured: AEs Prior to Dosing: From signing the informed consent form (ICF) to first dose of study drug. TEAEs: From first dose of study drug up to End of Study (Week 52).
Secondary outcomes (2)
Change From Baseline Over Time in Rate of Ureagenesis
The change from baseline 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 52 weeks after the IV administration of DTX301. Sodium acetate was used as a tracer to measure the rate of ureagenesis.
Rate of ureagenesis was derived in the following manner:
- Derive area under the curve from time zero to 240 minutes (AUC0-240min) of absolute 13C-urea (µmol/l/min) estimated by the linear trapezoidal rule
- Derive percent of normal AUC0-240min of absolute 13C-urea by dividing AUC0-240min of absolute 13C-urea (µmol*min/L) by 669.56 µmol*min/L (i.e. the AUC0-240min of absolute 13C-urea for an adult control)
- Derive rate of ureagenesis by multiplying % of normal AUC0-240min of absolute 13C-urea by 300 µmol*h/kg (i.e. the approximate rate of ureagenesis in healthy adults).
Measured: Baseline (Day 0), Weeks 6, 12, 20, 24, End of Study (Week 52). AUC was derived based on the following time points: 0.5, 1, 1.5, 2, 3, and 4 hours postdose.
Change From Baseline Over Time in Area Under the Curve From Time Zero to 24 Hours (AUC0-24) of Plasma Ammonia
Measured: Baseline (Day 0), Weeks 6, 12, 24, End of Study (Week 52). AUC was derived based on predose (time 0) and approximately 2, 4, 8, 12, 16, 20, 24 hours (±5 minutes) postdose.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Dec 2016 (estimated)
- Study start31 Jul 2017
- Primary completion16 Dec 2021
- Study completion16 Dec 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Ornithine Transcarbamylase (OTC) DeficiencyStudies of the same condition, open and under way.
- More trials run by Ultragenyx Pharmaceutical IncThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ultragenyx Pharmaceutical Inc
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Ultragenyx Pharmaceutical Inc
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02991144
- Sponsor's protocol ID
- 301OTC01
- Other IDs
- 2016-001057-40, 2016
- Acronym
- CAPtivate
- Status last verified
- Jan 2023
- First submitted
- 9 Dec 2016
- Last updated
- 26 Jan 2023
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No