Treatment for Arginase 1 Deficiency in Young Children

A Phase 3 Open-Label Study of Safety, Pharmacokinetics, and Activity of Weekly Subcutaneous Pegzilarginase in Subjects <24 Months Old with Arginase 1 Deficiency

This study is testing a new weekly injection for young children with Arginase 1 Deficiency to see if it is safe and helps improve their condition.

Quick facts

• Phase: Phase 3
• Study type: Interventional
• Enrollment: 3 (estimated)
• Ages: 1 Day to 24 Months
• Sex: All
• Sponsor: Immedica Pharma AB (Industry-sponsored)
• Locations: 3 sites (Graz and 2 other locations)
• Trial ID: NCT06582524 on ClinicalTrials.gov

What this trial studies

This open-label, multicentre study evaluates the safety and effectiveness of pegzilarginase administered weekly via subcutaneous injection in children under 24 months old diagnosed with Arginase 1 Deficiency (ARG1-D). The study includes a screening phase lasting up to 4 weeks to confirm eligibility and establish baseline plasma arginine levels, followed by a 12-week treatment period and an 8-week safety follow-up. The primary focus is on assessing pharmacokinetics and pharmacodynamics of the treatment.

Who should consider this trial

Good fit: Ideal candidates for this study are infants and toddlers under 24 months with a confirmed diagnosis of Arginase 1 Deficiency.

Not a fit: Patients who are older than 24 months or do not have a confirmed diagnosis of Arginase 1 Deficiency will not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve the management of Arginase 1 Deficiency in young patients, potentially leading to better health outcomes.

How similar studies have performed: While this approach is focused on a specific age group and condition, similar studies have shown promise in treating metabolic disorders with enzyme replacement therapies.

Eligibility criteria

Inclusion Criteria:

1. Subjects must be \< 24 months of age on the date of informed consent
2. Confirmed diagnosis of ARG1-D documented in medical records by at least 1 of the following methods:

   1. elevated plasma arginine levels
   2. a mutation analysis revealing a pathogenic variant
   3. red blood cell (RBC) arginase activity
3. Subjects must weigh \> 8 kg due to clinical trial related blood collection volumes required
4. Written informed consent by parent/legal guardian, in accordance with national stipulations, which includes compliance with the requirements and restrictions listed in the informed consent form and in this protocol
5. At least one value of plasma arginine ≥ 180 μM during screening
6. Documented confirmation from the Investigator and/or dietitian that the subject can:

   1. attempt to maintain a stable, age-appropriate level of protein consumption, including natural protein, and EAA supplementation within approximately ± 15% of dietitian recommended diet
   2. attempt to maintain current use of ammonia scavengers, if prescribed

Exclusion Criteria:

1. Other medical condition(s) or comorbidity(ies) that, in the opinion of the Investigator, would interfere with study compliance or data interpretation
2. Hyperammonaemic episode (plasma ammonia levels \> 100 μM) with ≥ 1 symptom related to hyperammonaemia requiring hospitalisation or emergency room management within the 4 weeks before the first dose of study drug
3. Active infection requiring anti-infective therapy within \< 2 weeks before first dose of study drug
4. Known active infection with human immunodeficiency virus, hepatitis B, or hepatitis C
5. History of hypersensitivity to polyethylene glycol (PEG) or any of the excipients included in the study drug that, in the judgment of the Investigator, puts the subject at unacceptable risk for AEs
6. Currently participating in another therapeutic clinical study or has received any investigational agent within 30 days (or 5 half-lives, whichever is longer) prior to first dose of study drug
7. Previous liver or haematopoietic stem cell transplant
8. Use of botulinum toxin within 16 weeks prior to first dose

Where this trial is running

Graz and 2 other locations

• Univ. Klinik für Kinder- und Jugendheilkunde Medizinische Universität — Graz, Austria (Recruiting)
• Unidade de Doenças Metabólicas Pediatria, Hospital Santa Maria — Lisboa, Portugal (Recruiting)
• Bradford Royal Infirmary Duckworth Lane — Bradford, United Kingdom (Recruiting)

Study contacts

• Study coordinator: Mattias Rudebeck, PhD MSc BMedSc

Conditions Arginase 1 Deficiency