A clinical study of a virus transferring the gene for human Ornithine Transcarbamylase (OTC) in patients older than 12 years old with late-onset OTC deficiency
- Conditions
- ate-onset Ornithine transcarbamylase (OTC) deficiencyTherapeutic area: Diseases [C] - Congenital, Hereditary, and Neonatal Diseases and Abnormalities [C16]MedDRA version: 20.0Level: LLTClassification code 10071107Term: Ornithine transcarbamylase deficiencySystem Organ Class: 10010331 - Congenital, familial and genetic disorders
- Registration Number
- EUCTR2020-003384-25-DE
- Lead Sponsor
- ltragenyx Pharmaceutical Inc.
- Brief Summary
Not available
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Authorised-recruitment may be ongoing or finished
- Sex
- All
- Target Recruitment
- 50
Eligible individuals must meet all of the following criteria:
1. Male or female patient 12 years of age or older at the time of signed informed consent.
2. Provide informed consent after the nature of the study has been explained, and prior to any research-related procedures. If a minor, willing and able (if possible) to provide assent and have a legally authorized representative provide informed consent after the nature of the study has been explained, and prior to any research-related procedures.
3. Confirmed clinical diagnosis of late-onset OTC deficiency with historical documentation by enzymatic (ie, liver biopsy), biochemical (ie, hyperammonemia in the presence of elevated plasma glutamine, low citrulline, and elevated spot urine orotic acid), or molecular testing (ie, OTC analysis).
4. Documented history of = 1 symptomatic hyperammonemia episode with ammonia level = 100 µmol/L for confirmation of clinical disease.
5. Patient is currently receiving ammonia scavenger therapy and/or protein-restricted diet, is free from symptomatic hyperammonemia and has not required emergent active intervention for hyperammonemia within 4 weeks before screening/baseline.
6. Plasma 24-hour ammonia (AUC0-24) is = 4800 µmol*h/L at screening. If the ammonia AUC0-24 is inconsistent with the patient’s clinical status, the assessment may be repeated to ensure accurate results.
7. If on ongoing daily ammonia scavenger therapy, must be at stable daily dose(s) for = 4 weeks prior to screening.
8. If on a protein-restricted diet, must be on a stable protein-restricted diet as evidenced by a stable amount of total protein intake (ie, daily protein intake in grams per day does not vary more than 20%) for = 4 weeks prior to screening.
9. Willing and able to comply with study procedures and requirements, including periodic inpatient hospitalizations, frequent blood and urine collections, blood collections over a 24-hour period, questionnaires, cognitive assessments, and patient/caregiver reported outcome assessments. If a minor, must have a caregiver(s) willing and able to assist in all applicable study requirements.
10. From the time written informed consent is provided through Week 128, females of childbearing potential and fertile males must consent to use highly effective contraception as defined by the United States Food and Drug Administration (FDA) and Clinical Trial Facilitation Coordination Group (CTFG) Recommendations Related to Contraception and Pregnancy in Clinical Trials. If female, agree not to become pregnant. If male, agree to not father a child or donate sperm.
Are the trial subjects under 18? yes
Number of subjects for this age range: 12
F.1.2 Adults (18-64 years) yes
F.1.2.1 Number of subjects for this age range 38
F.1.3 Elderly (>=65 years) no
F.1.3.1 Number of subjects for this age range
Individuals who meet any of Exclusion Criteria 1 to 16 will not be eligible to participate in the study. Individuals who meet Exclusion Criteria 18 will not be eligible to undergo the URT:
1. Liver transplant, including hepatocyte cell therapy/transplant.
2. History of liver disease as evidenced by any of the following: portal hypertension, ascites, splenomegaly, esophageal varices, hepatic encephalopathy, or a liver biopsy with evidence of stage 3 fibrosis.
3. Significant hepatic inflammation or cirrhosis as evidenced by imaging or any of the following laboratory abnormalities: alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 1.5 × ULN, total bilirubin > 1.5 × ULN (except if patient has a diagnosis of Gilbert's syndrome), alkaline phosphatase > 2.5 × ULN. NOTE: Any of the LFTs may be retested.
4. Estimated glomerular filtration rate < 60 mL/min/1.73 m2 at screening by the CKD-EPI 2021 creatinine-based formula (Inker et al., 2021) for patients = 18 years of age or the Schwartz bedside formula (Schwartz and Work, 2009) for patients < 18 years of age.
5. Evidence of active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, documented by current use of antiviral therapy for HBV or HCV or by hepatitis B surface antigen (HBsAg) or HCV RNA positivity. NOTE: Patients with a history of HCV infection must have documentation of 2 negative viral assays by PCR, collected at least 6 months apart, to be considered negative for HCV. Patients with a history of HCV infection who test positive for HCV RNA at screening can be rescreened once, after they have been treated and have documentation of at least 2 negative samples collected at least 6 months apart.
6. History of human immunodeficiency virus (HIV) infection AND any of the following: CD4+ cell count < 350 cells/mm3, change in antiretroviral therapy regimen within 6 months prior to Baseline (Day 0), or plasma viral load > 200 copies/mL, documented on 2 separate occasions, as measured by PCR.
7. Active infection (viral or bacterial).
8. Detectable pre-existing antibodies to the AAV8 capsid.
9. History of a malignancy for which the patient has received treatment in the past 2 years except for prostate cancer treated with watchful waiting or surgically removed nonmelanoma skin cancer.
10. Any of the following that, in the judgment of the Investigator, places the subject at increased risk for adverse effects:
• Known hypersensitivity to DTX301, its excipients, or its placebo
• Known hypersensitivity to prednisolone, its excipients, or its placebo
11. Chronic use of inhibitors of urea synthesis (eg, valproic acid) or drugs that significantly affect renal clearance (eg, probenecid).
12. Presence or history of any condition that, in the view of the Investigator, would interfere with participation, pose undue risk, or confound interpretation of results, including but not limited to:
• Underlying conditions that may require systemic corticosteroids if the condition worsens (eg, autoimmune disorders)
• Patient in a catabolic state (eg, due to current infection), or in whom a catabolic state may be reasonably foreseeable (eg, due to planned procedures)
• Patient is considered vulnerable by local regulations (eg, imprisoned or institutionalized)
13. Marked neurological deficit or compromise that, in the Investigator’s opinion, would interfere with the patient's safety or ability to participate in the study.
14. Pregnant or breastfeeding or planning to become pregnant within 64 w
Study & Design
- Study Type
- Interventional clinical trial of medicinal product
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Main Objective: To evaluate the efficacy of DTX301 on the improvement of OTC function by maintaining safe plasma ammonia levels;Secondary Objective: - To evaluate the efficacy of DTX301 in 3 response categories<br>- To evaluate the effect of DTX301 on OTC deficiency patient health outcomes<br>- To evaluate the effect of DTX301 on occurrence of HACs <br>- To evaluate the effect of DTX301 on plasma ammonia over time<br>- To evaluate the safety of DTX301 <br>- To charakterize the immune response to OTC protein (anti-OTC antibodies)<br>;Primary end point(s): • Percentage of patients at Week 64 who have achieved complete response (Modified Intention-to-Treat [mITT], DTX301 vs Placebo, test for superiority)<br>• Plasma ammonia as measured by 24-hour ammonia (AUC0-24) at Week 64 for all subjects as assessed by the geometric mean ratio (ITT, DTX301 vs Placebo, test for non-inferiority);Timepoint(s) of evaluation of this end point: Week 64
- Secondary Outcome Measures
Name Time Method Secondary end point(s): • Percentage of patients at Week 64 who have achieved complete response, response, or no response (mITT, DTX301 vs Placebo, test for superiority)<br>• PGIC-Overall Change score (DTX301 vs Placebo) at Week 64<br>• Rate of HACs from baseline to Week 64 compared to the 15-month pre-enrollment period (DTX301 vs Placebo)<br>• Change in plasma ammonia (AUC0-24) after 64 weeks of DTX301 exposure (comparison between those who had a reduction of baseline disease management vs not)<br>• Change in plasma ammonia (AUC0-24) from baseline to Week 64 for all patients (DTX301 vs Placebo)<br>• Incidence of TEAEs, TESAEs, treatment-related TEAEs, treatment-related TESAEs, and AESIs<br>• Clinically significant changes in laboratory values, physical examination results, and vital sign measurements<br>• Development of anti-OTC antibodies;Timepoint(s) of evaluation of this end point: Week 64