Pegzilarginase
Pegzilarginase is an enzyme replacement therapy designed to treat Arginase 1 Deficiency (ARG1-D), a rare inherited metabolic disorder. It provides an exogenous source of the human arginase 1 enzyme to reduce persistently elevated plasma arginine levels in patients with this condition.
Pegzilarginase is an enzyme replacement therapy used to manage Arginase 1 Deficiency by supplementing deficient arginase 1 enzyme activity.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- A16AB24
- RxNorm
- 2738648
- Generic
- Pegzilarginase
- Class
- atc-a16
- Brands
- Loargys
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- injection
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 4.0 mg/kg once weekly
- Maximum
- consult physician
- Frequency
- once weekly
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 4.0 mg/kg once weekly
- Maximum
- consult physician
- Frequency
- once weekly
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 4.0 mg/kg once weekly
- Maximum
- consult physician
- Frequency
- once weekly
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
11 groupspregnancy
first trimesteruse only if clearly needed
avoid use during pregnancy unless potential benefits justify potential risks to the fetus
regular fetal monitoring and ultrasound assessments
pregnancy
second trimesteruse only if clearly needed
continue treatment only if benefits outweigh risks to fetus
regular fetal monitoring
pregnancy
third trimesteruse only if clearly needed
consider risks versus benefits close to delivery
fetal monitoring and assessment of neonatal condition
lactation
breastfeedingno adjustment recommended
discontinue breastfeeding or discontinue drug based on importance to mother
monitor infant for any adverse effects
pediatric_age
children 2 to 11 yearsweight-based dosing
approved for use in pediatric patients with arginase 1 deficiency
regular monitoring of arginine levels and growth parameters
pediatric_age
adolescents 12 to 17 yearsweight-based dosing
approved for use in pediatric patients
regular monitoring of arginine levels
geriatric
elderly 65 and olderstart at lower end of dosing range
use with caution due to limited data in elderly population
close monitoring of renal function and overall tolerability
Use with caution and monitor for adverse effects.
renal_impairment
mild renal impairmentno specific adjustment
use with caution and monitor closely
monitor renal function
renal_impairment
severe renal impairmentnot recommended
use not recommended due to lack of data
not applicable
hepatic_impairment
mild to moderate hepatic impairmentuse with caution
use with caution due to limited data
monitor liver function tests
hepatic_impairment
severe hepatic impairmentnot recommended
use not recommended due to lack of data
not applicable
Statistics and clinical data
Drug class
Classification as recombinant human arginase 1 enzyme replacement therapy
FDA approval year
FDA approval for treatment of arginase 1 deficiency
Indication
Approved for treatment of arginase 1 deficiency in adults and pediatric patients 2 years and older
Mechanism of action
Enzyme replacement to reduce elevated arginine levels
Treatment of Arginase 1 Deficiency (ARG1-D) in adult and pediatric patients. ARG1-D is a rare inherited metabolic disease characterized by deficiency of the arginase 1 enzyme, leading to accumulation of arginine in the blood.
Pegzilarginase provides an exogenous source of functional human arginase 1 enzyme activity. The enzyme catalyzes the hydrolysis of arginine into ornithine and urea, thereby reducing the persistent hyperargininemia associated with ARG1-D.
This is a specialized enzyme replacement therapy for a rare genetic metabolic disorder. Treatment should be supervised by physicians experienced in managing patients with urea cycle disorders or inherited metabolic diseases. Regular monitoring of plasma arginine levels is important to assess treatment response.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy