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CompletedNCT06582524Updated May 22, 2026Results posted

Pegzilarginase in Subjects <24 Months Old With Arginase 1 Deficiency

A Phase 3 interventional study of Pegzilarginase in Arginase 1 Deficiency, sponsored by Immedica Pharma AB. Completed at 3 sites in 3 countries. Open to participants aged 1 Day to 24 Months. Per ClinicalTrials.gov, last updated 2026-05-22.

Sponsored by Immedica Pharma AB · Phase 3, Interventional, and Treatment

Phase
Phase 3
Study type
Interventional
Enrollment
3
Allocation
Not applicable
Ages
1 Day to 24 Months
Sex
All
01

Study summary

This is an open-label, multicentre study to evaluate the safety, PK, and activity (PD) of weekly subcutaneous (SC) administration of pegzilarginase in subjects with ARG1-D who are \< 24 months of age. The study consists of a screening period of up to 4 weeks, a subsequent 12-week treatment period, and a safety follow-up period of 8 weeks.

Read the detailed description

CAEB1102-301A is an open-label, single-arm, non-controlled, repeat dosing, multicentre study to evaluate the safety, PK, and activity (PD) of weekly SC administration of pegzilarginase over 12 weeks in subjects with ARG1-D who are \< 24 months of age.

This study will consist of:

  • A screening period of up to 4 weeks to ensure the subjects meet the study eligibility criteria and establish baseline plasma arginine
  • A treatment period of 12 weeks
  • A safety follow-up period of 8 weeks with visits 1 week and 8 weeks after the last dose.
02

Conditions studied

  • Arginase 1 Deficiency
03

In context

Lead sponsor

Immedica Pharma AB is the lead sponsor of 7 studies on the registry; 1 is open to participants now.

Of its 5 completed or terminated interventional studies of FDA-regulated products, 2 (40%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
1 Day to 24 Months
Sexes eligible
All
Accepts healthy volunteers
No

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

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
05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
3 participants (actual)

Study arms

  • Experimental
    Weekly subcutaneous (SC) administration of pegzilarginase

    All subjects will receive a once weekly (QW) SC dose of pegzilarginase for 12 weeks

    Drug: Pegzilarginase

Interventions

  • DrugPegzilarginase

    SC administration of pegzilarginase over 12 weeks in subjects with ARG1-D who are \< 24 months of age

    Also known as: Loargys

06

What researchers measure

Primary outcomes

  1. Change From Baseline in Plasma Arginine Concentrations in Subjects <24 Months of Age With Arginase 1 Deficiency (ARG1-D).

    To evaluate the effect of pegzilarginase on plasma arginine concentrations in subjects \<24 months of age with arginase 1 deficiency (ARG1-D).

    Time frame: From baseline up to 12 weeks.

Secondary outcomes

  1. Pharmacokinetic (PK) Profile of Pegzilarginase: Half-life (T½).

    PK parameters with evaluation of half-life (T½).

    Time frame: From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.

  2. Pharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Tmax).

    PK parameters with evaluation on time to maximum observed concentration (Tmax).

    Time frame: From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.

  3. Pharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Cmax).

    PK parameters with evaluation of maximum observed concentration (Cmax).

    Time frame: From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.

  4. Pharmacokinetic (PK) Profile of Pegzilarginase: Area Under the Plasma Drug Concentration-time Curve.

    PK parameters with evaluation on area under the plasma drug concentration-time curve.

    Time frame: From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.

  5. Pharmacodynamic (PD) Response of Pegzilarginase: Anti-drug Antibodies (ADAs).

    PD response evaluation, anti-drug antibodies (ADAs).

    Time frame: From baseline up to 12 weeks. Samples taken on visit 1, 2, 4, 8 and 13 (pre-dose if on a dosing day).

  6. Pharmacodynamic (PD) Response of Pegzilarginase: Levels of Plasma Arginine.

    PD response evaluation, levels of plasma arginine. Arginine within guidance level.

    Time frame: From baseline up to 12 weeks. Samples taken on visit 1, 2, 4, 8 and 13 (pre-dose if on a dosing day).

  7. Changes From Baseline in Physical Function: GMFM-66.

    Changes in physical function after 12 weeks of pegzilarginase treatment as measured by Gross Motor Function Measure (GMFM)-66 Parts A through E (total score). The Gross Motor Function Measure (GMFM) utilize a 4-point scoring system for each item across dimensions A-E. The minimum score is 0; the maximum score is 198, with a higher score representing better gross motor function.

    Time frame: From baseline up to 12 weeks.

07

Results

Posted Apr 30, 2026

Participant flow

Participants were enrolled at 3 different study sites between 30 August 2024 and 17 June 2025.

Participant flow — Overall Study
MilestoneWeekly Subcutaneous (SC) Administration of Pegzilarginase
Started3
Completed3
Not completed0

Outcome measures

PrimaryChange From Baseline in Plasma Arginine Concentrations in Subjects <24 Months of Age With Arginase 1 Deficiency (ARG1-D).

To evaluate the effect of pegzilarginase on plasma arginine concentrations in subjects \<24 months of age with arginase 1 deficiency (ARG1-D).

Time frame:
From baseline up to 12 weeks.
Reported as:
Mean · μM
Change From Baseline in Plasma Arginine Concentrations in Subjects <24 Months of Age With Arginase 1 Deficiency (ARG1-D).
μMWeekly Subcutaneous (SC) Administration of Pegzilarginase
Change From Baseline in Plasma Arginine Concentrations in Subjects <24 Months of Age With Arginase 1 Deficiency (ARG1-D).-221.53 ± 81.26
SecondaryPharmacokinetic (PK) Profile of Pegzilarginase: Half-life (T½).

PK parameters with evaluation of half-life (T½).

Time frame:
From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.
Reported as:
Geometric mean · hours
Pharmacokinetic (PK) Profile of Pegzilarginase: Half-life (T½).
hoursWeekly Subcutaneous (SC) Administration of Pegzilarginase
Pharmacokinetic (PK) Profile of Pegzilarginase: Half-life (T½).52.0 ± 0.836
SecondaryPharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Tmax).

PK parameters with evaluation on time to maximum observed concentration (Tmax).

Time frame:
From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.
Reported as:
Geometric mean · hours
Pharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Tmax).
hoursWeekly Subcutaneous (SC) Administration of Pegzilarginase
Pharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Tmax).31.0 ± 5.69
SecondaryPharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Cmax).

PK parameters with evaluation of maximum observed concentration (Cmax).

Time frame:
From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.
Reported as:
Geometric mean · μg/mL
Pharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Cmax).
μg/mLWeekly Subcutaneous (SC) Administration of Pegzilarginase
Pharmacokinetic (PK) Profile of Pegzilarginase: Maximum Observed Concentration (Cmax).0.646 ± 24.6
SecondaryPharmacokinetic (PK) Profile of Pegzilarginase: Area Under the Plasma Drug Concentration-time Curve.

PK parameters with evaluation on area under the plasma drug concentration-time curve.

Time frame:
From baseline up to 12 weeks. Within 1 hour pre-dose a sample was taken on visits 1, 2, 4, 6, 8, 10, and 13. A post-dose sample was taken 12 - 48 hours after dosing on visits 2, 4, and 10.
Reported as:
Geometric mean · hours x µg/mL
Pharmacokinetic (PK) Profile of Pegzilarginase: Area Under the Plasma Drug Concentration-time Curve.
hours x µg/mLWeekly Subcutaneous (SC) Administration of Pegzilarginase
Pharmacokinetic (PK) Profile of Pegzilarginase: Area Under the Plasma Drug Concentration-time Curve.64.6 ± 23.4
SecondaryPharmacodynamic (PD) Response of Pegzilarginase: Anti-drug Antibodies (ADAs).

PD response evaluation, anti-drug antibodies (ADAs).

Time frame:
From baseline up to 12 weeks. Samples taken on visit 1, 2, 4, 8 and 13 (pre-dose if on a dosing day).
Reported as:
Count of participants · Participants
Pharmacodynamic (PD) Response of Pegzilarginase: Anti-drug Antibodies (ADAs).
ParticipantsWeekly Subcutaneous (SC) Administration of Pegzilarginase
Pharmacodynamic (PD) Response of Pegzilarginase: Anti-drug Antibodies (ADAs).0
SecondaryPharmacodynamic (PD) Response of Pegzilarginase: Levels of Plasma Arginine.

PD response evaluation, levels of plasma arginine. Arginine within guidance level.

Time frame:
From baseline up to 12 weeks. Samples taken on visit 1, 2, 4, 8 and 13 (pre-dose if on a dosing day).
Reported as:
Count of participants · Participants
Pharmacodynamic (PD) Response of Pegzilarginase: Levels of Plasma Arginine.
ParticipantsWeekly Subcutaneous (SC) Administration of Pegzilarginase
Pharmacodynamic (PD) Response of Pegzilarginase: Levels of Plasma Arginine.3
SecondaryChanges From Baseline in Physical Function: GMFM-66.

Changes in physical function after 12 weeks of pegzilarginase treatment as measured by Gross Motor Function Measure (GMFM)-66 Parts A through E (total score). The Gross Motor Function Measure (GMFM) utilize a 4-point scoring system for each item across dimensions A-E. The minimum score is 0; the maximum score is 198, with a higher score representing better gross motor function.

Time frame:
From baseline up to 12 weeks.
Reported as:
Mean · Points
Changes From Baseline in Physical Function: GMFM-66.
PointsWeekly Subcutaneous (SC) Administration of Pegzilarginase
Changes From Baseline in Physical Function: GMFM-66.21.0 ± 13.9

Adverse events

Collected over From first dose until last safety follow up, week 20 (±7days).. Non-serious events are listed at a 5% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Weekly Subcutaneous (SC) Administration of Pegzilarginase0/3 (0%)0/3 (0%)3/3 (100%)
Most frequent other events
Showing 10 of 16
Most frequent other events
EventWeekly Subcutaneous (SC) Administration of Pegzilarginase
PyrexiaGeneral disorders2/3
AnemiaBlood and lymphatic system disorders1/3
DiarrheaGastrointestinal disorders1/3
VomitingGastrointestinal disorders1/3
Condition aggravatedGeneral disorders1/3
Injection site erythemaGeneral disorders1/3
Febrile infectionInfections and infestations1/3
Respiratory syncytial virus infectionInfections and infestations1/3
Respiratory tract infectionInfections and infestations1/3
Respiratory tract infection bacterialInfections and infestations1/3

Baseline characteristics

Age, Continuous
Age, Continuous(Months)Weekly Subcutaneous (SC) Administration of Pegzilarginase
Mean20.3 ± 4.6
Sex: Female, Male
Sex: Female, Male(Participants)Weekly Subcutaneous (SC) Administration of Pegzilarginase
Female1
Male2
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Weekly Subcutaneous (SC) Administration of Pegzilarginase
American Indian or Alaska Native0
Asian0
Native Hawaiian or Other Pacific Islander0
Black or African American1
White2
More than one race0
Unknown or Not Reported0
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Weekly Subcutaneous (SC) Administration of Pegzilarginase
Hispanic or Latino0
Not Hispanic or Latino3
Unknown or Not Reported0
Baseline plasma arginine levels
Baseline plasma arginine levels(μM)Weekly Subcutaneous (SC) Administration of Pegzilarginase
Mean228.67 ± 133.67
08

Study locations

3 sites
  • Univ. Klinik für Kinder- und Jugendheilkunde Medizinische Universität
    Graz, A-8036, Austria
  • Unidade de Doenças Metabólicas Pediatria, Hospital Santa Maria
    Lisbon, Portugal
  • Bradford Royal Infirmary Duckworth Lane
    Bradford, BD9 6RJ, United Kingdom
09

References and documents

Study documents

  • Study protocol · May 31, 2024
  • Statistical analysis plan · Aug 7, 2025

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 22, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT06582524
Lead sponsor
Immedica Pharma AB
Responsible party
Sponsor
First posted
Sep 3, 2024
Start date
Aug 30, 2024
Primary completion
Jun 17, 2025
Completion
Jun 17, 2025
Results posted
Apr 30, 2026
Last update
May 22, 2026

Study contacts

Mattias Rudebeck, PhD MSc BMedSc
study director · Immedica Pharma AB

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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