An Open-label Study to Investigate ECUR-506 in Male Babies Less Than 9 Months of Age With Neonatal Onset OTC Deficiency

iECURE

Status and phase: Enrolling; Phase 2; Phase 1

Conditions: Ornithine Carbamoyltransferase Deficiency (Disorder); Urea Cycle Disorders, Inborn; Ornithine Transcarbamylase Deficiency Disease; Ornithine Transcarbamylase Deficiency

Treatments: Genetic: ECUR-506

Study type: Interventional

Funder types: Industry

Identifiers

NCT06255782

OTC HOPE (Other Identifier)

ECUR-506-OTC-101

Details and patient eligibility

About

Ornithine Transcarbamylase (OTC) deficiency, the most common urea cycle disorder, is an inherited metabolic disorder caused by a genetic defect in a liver enzyme responsible for detoxification of ammonia. Individuals with OTC deficiency can build-up excess levels of ammonia in their blood, potentially resulting in devastating consequences, including cumulative and irreversible neurological damage, coma and death. The severe form of the condition emerges shortly after birth and is more common in boys than girls.

This is a Phase 1/2/3, open-label, multicenter, safety, efficacy, and dose finding study of ECUR-506 in male babies with neonatal onset OTC deficiency. The primary objective of this study is to evaluate the safety, tolerability, and efficacy of up to three dose levels of ECUR-506 following intravenous (IV) administration of a single dose.

Full description

The study drug, ECUR-506, is an investigational gene editing therapy. Gene editing is a way to repair, replace, or introduce new copies of genes that don't work. The study drug contains a working copy of the OTC gene that will be delivered by an IV infusion. It also contains a gene to encode the editing enzyme which is the part of the study drug that can cut DNA so that the OTC gene can be inserted. The study drug was designed to introduce a working copy of the OTC gene and a gene to encode the editing enzyme. A gene cannot enter cells by itself, it needs a delivery mechanism to move the gene into the cells. In this study, a commonly used virus called adeno-associated virus (AAV) is used to enter the cells and deliver the genes.

Enrollment: 8 estimated patients

Sex: Male

Ages: 24 hours to 7 months old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria:

1. Male sex
2. Gestational or adjusted (corrected) gestational age ≥ 37 weeks
3. Age at screening is 24 hours to 7 months
4. Weight ≥ 3.5 kg and ≤ 13.5 kg at screening
5. Has received age-appropriate vaccinations
6. Genetically confirmed OTCD
7. Severe neonatal OTCD defined by hyperammonemic crisis with elevated ammonia level of >560 μmol/L and clinical symptoms within first week of life
8. Current or historical biochemical profile consistent with OTCD
9. Participant's parent(s)/LAR must be able to comprehend and be willing to provide a signed IRB/IEC-approved ICF.

Key Exclusion Criteria:

1. Neonatal diagnosis of severe to profound Hypoxic Ischemic Encephalopathy due to birth injury
2. Requiring urgent liver transplant due to liver failure as assessed by the PI.
3. Contiguous gene deletion involving the OTC gene and including at least the CYBB gene on the telomeric side or the TSPAN7 gene on the centromeric side.
4. Known or suspected major organ injury/dysfunction/anomalies.
5. Vital sign abnormalities
6. Laboratory abnormalities outside of laboratory normal ranges for urinalysis, complete blood count, and comprehensive metabolic panel that are attributable to comorbidities unrelated to OTCD
7. Treatment with any other gene therapy or gene editing therapy
8. Co-enrollment in any other clinical study unless approved by the sponsor.
9. Any condition, that in the opinion of the Investigator, would compromise the safety of the participant or study data
10. Documented vertical transmission of HepA/HepB/HepC
11. Documented in-utero teratogen, substance, and/or alcohol exposure, which in the opinion of the Investigator may increase the participant's risk of developmental delays, congenital anomalies, and/or significant medical complications

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Sequential Assignment

Masking: None (Open label)

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8 participants in 3 patient groups

Low Dose Level

Experimental group

Description:

Participants will receive the Low Dose of ECUR-506 delivered one time via IV Infusion.

Treatment:

Genetic: ECUR-506

High Dose Level

Experimental group

Description:

Participants will receive a higher dose of ECUR-506 delivered one time via IV infusion.

Treatment:

Genetic: ECUR-506

Intermediate Dose Level

Experimental group

Description:

Additional Cohorts based on recommendations of DMC review of safety and efficacy data.

Treatment:

Genetic: ECUR-506