Study for Adolescents and Adults With Ornithine Transcarbamylase Deficiency to Evaluate Safety and Tolerability of ARCT-810

NCT05526066 | Terminated Phase 2 DMC FDA Drug

• 1 other identifier: ARCT-810-03
• Study Type: interventional
• Target: 8
• Locations: 6 countries
• Sites: 14

Brief Summary

The primary objective is to evaluate the safety and tolerability of repeated doses of intravenously administered ARCT-810.

Conditions

Ornithine Transcarbamylase Deficiency; OTC Deficiency; OTCD

Keywords

OTC; OTCD; Ornithine; Transcarbamylase; mRNA; Ornithine Transcarbamylase Deficiency; OTC Deficiency

Outcome Measures

Primary Outcomes (1)

• Incidence, severity and dose-relationship of adverse events (AEs)

  Safety and tolerability of ARCT-810 assessed by determining the number and severity of AEs by dose level

  Week 23

Secondary Outcomes (11)

• Plasma concentration area under the curve after first and last doses of ARCT-810

  Up to 17 Weeks

• Maximum observed plasma concentration (Cmax) after first and last doses of ARCT-810

  Up to 17 Weeks

• Time at which Cmax occurred after first and last doses of ARCT-810

  Up to 17 Weeks

• AUC0-inf after first and last doses of ARCT-810

  Up to 17 Weeks

• AUCExtrap after first and last doses of ARCT-810

  Up to 17 Weeks

Study Arms (2)

ARCT-810

EXPERIMENTAL

Participants receive an initial intravenous (IV) infusion ARCT-810. If considered safe and well tolerated, participants will receive up to 5 additional IV infusions of ARCT-810 administered at 14-day intervals.

Biological: ARCT-810

Placebo, Normal Saline

PLACEBO COMPARATOR

Participants receive an initial IV infusion of placebo. If considered safe and well tolerated, participants receive up to 5 additional IV infusions of placebo administered at 14-day intervals.

Other: Placebo

Interventions

ARCT-810 BIOLOGICAL

ARCT-810 is messenger RNA (mRNA) coding for Ornithine Transcarbamylase (OTC) formulated in a lipid nanoparticle (LNP).

ARCT-810

Placebo OTHER

Normal Saline

Placebo, Normal Saline

Eligibility Criteria

• Age: 12 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Adequate cognitive ability to understand study requirements and give informed consent
• Males and females aged 12 to 65 years inclusive, at Screening
• Documented diagnosis of OTC deficiency
• Clinical stability (no clinical symptoms of hyperammonemia within 1 month, no hospitalizations for metabolic decompensation within 3 months, ≤ 2 hospitalizations within 1 year)
• Stable protein-restricted diet, dietary supplements, and ammonia scavenger regimen (if applicable) for at least 28 days.
• BMI = 18.0 - 32.0 kg/m2, inclusive for adults, and \>5th percentile for adolescents ≥12 to 17 years
• Must be willing to adhere to contraception guidelines

You may not qualify if:

• History of any OTC gene therapy, or history of liver-derived stem cell therapy in the past 3 years
• History of severe allergic reaction to liposomal or PEG-containing products
• Abuse of illicit drugs, medications or alcohol
• Clinically significant laboratory abnormalities on screening labs

Sponsors & Collaborators

• Arcturus Therapeutics, Inc.: lead

Study Sites (14)

Cliniques Universitaires Saint Luc

Brussels, 1200, Belgium

Location

Hôpitaux Universitaires de Marseille - Hôpital de la Timone

Marseille, 13005, France

Location

Assistance Publique - Hôpitaux de Paris (AP-HP) - Hôpital Necker-Enfants Malades

Paris, France

Location

Azienda Ospedaliera di Padova

Padua, 35128, Italy

Location

IRCCS Ospedale Pediatrico Bambino Gesu

Rome, 00165, Italy

Location

Hospital Clínic de Barcelona

Barcelona, Spain

Location

Hospital Sant Joan de Déu

Barcelona, Spain

Location

Hospital Universitario 12 de Octubre

Madrid, 28041, Spain

Location

Complejo Hospitalario Universitario de Santiago (CHUS) - Hospital Clínico Universitario

Santiago de Compostela, 15706, Spain

Location

Karolinska Universitetssjukhuset - Astrid Lindgrens Barnsjukhus

Stockholm, SE- 171 64, Sweden

Location

University Hospitals Birmingham NHS Foundation Trust - Queen Elizabeth Hospital Birmingham

Birmingham, UK, B15 2PR, United Kingdom

Location

Great Ormond Street Hospital for Children NHS Foundation Trust

London, UK, WC1N 3JH, United Kingdom

Location

University College London Hospitals NHS Foundation Trust - National Hospital for Neurology and Neurosurgery

London, United Kingdom

Location

Salford Royal NHS Foundation Trust - Salford Royal Hospital

Salford, M6 8HD, United Kingdom

Location

MeSH Terms

Conditions

Ornithine Carbamoyltransferase Deficiency Disease

Condition Hierarchy (Ancestors)

Urea Cycle Disorders, Inborn; Brain Diseases, Metabolic, Inborn; Brain Diseases, Metabolic; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Genetic Diseases, X-Linked; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Amino Acid Metabolism, Inborn Errors; Metabolism, Inborn Errors; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Double-Blinded
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: On Day 1, participants will receive a single dose of Study Drug via intravenous infusion. If the safety observations are considered acceptable, that participant will enter the multiple-dose portion of the study in which they will receive a further 5 doses of Study Drug on Days 15, 29, 43, 57 and 71.

Study Record Dates

• First Submitted: August 8, 2022
• First Posted: September 2, 2022
• Study Start: October 17, 2022
• Primary Completion: October 31, 2024
• Study Completion: October 31, 2024
• Last Updated: September 26, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1); FR (2); ES (4); SE (1); GB (4); IT (2)