Pegvaliase
Pegvaliase is an enzyme substitution therapy used to treat phenylketonuria (PKU) in adults who have inadequate blood phenylalanine control despite dietary restriction. As a PEGylated phenylalanine ammonia lyase (PAL), it converts phenylalanine into ammonia and trans-cinnamic acid, effectively replacing the deficient phenylalanine hydroxylase (PAH) enzyme activity characteristic of PKU.
An enzyme therapy for PKU that converts excess phenylalanine into harmless substances, used when dietary management alone is insufficient.
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
- A16AB19
- RxNorm
- 2046360
- Generic
- Pegvaliase
- Class
- atc-a16
- Brands
- Palynziq
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- prefilled syringe
- 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
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
10 groupspregnancy
first trimesteravoid if possible
use only if benefits outweigh potential risks; discontinue if pregnancy occurs
regular fetal monitoring and assessment of phenylalanine levels
pregnancy
second trimesteravoid if possible
continue only if benefits outweigh risks
regular fetal monitoring and phenylalanine level tracking
pregnancy
third trimesteravoid if possible
use only if benefits outweigh potential risks
regular fetal monitoring
lactation
breastfeedingno adjustment
decision to discontinue drug or breastfeeding should consider benefit to infant and mother
monitor infant for adverse effects
pediatric_age
under 18not recommended
not approved for patients under 18 years of age; use alternative treatments
n/a
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
over 65no specific adjustment
use with caution; start at lower end of dosing range
monitor renal function and for adverse reactions
Use with caution and monitor for adverse effects.
renal_impairment
mildno adjustment
no dose adjustment needed for mild renal impairment
standard monitoring
renal_impairment
moderate to severeno specific adjustment
use with caution; limited data in severe renal impairment
monitor renal function regularly
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderateno specific adjustment
use with caution; limited clinical data
monitor liver function tests
Use with caution and monitor for adverse effects.
alcohol_users
regular useavoid alcohol
avoid alcohol consumption as it may interfere with PKU management and increase risk of adverse effects
monitor phenylalanine levels
Use with caution and monitor for adverse effects.
Statistics and clinical data
Drug class
Pharmacological classification
Indication
Therapeutic indication
FDA approval year
Regulatory approval information
Mechanism of action
Pharmacological mechanism
Pegvaliase is indicated for phenylketonuria (PKU) in adults aged 18 years and older who have inadequate blood phenylalanine control despite dietary phenylalanine restriction or existing therapies.
Pegvaliase is a PEGylated phenylalanine ammonia lyase (PAL) enzyme that converts phenylalanine to ammonia and trans-cinnamic acid. This substitutes for the deficient phenylalanine hydroxylase (PAH) enzyme activity in PKU patients, effectively reducing blood phenylalanine concentrations.
Common adverse reactions include injection site reactions, arthralgia, and hypersensitivity reactions. Patients should be monitored for immune reactions and anaphylaxis. Regular blood phenylalanine monitoring is required during treatment. Not recommended for patients with known hypersensitivity to the active substance or excipients.
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