Last reviewed 2026-04-20 · How we verify

PEGVALIASE

Pegvaliase-pqpz converts phenylalanine to ammonia and trans-cinnamic acid, reducing blood phenylalanine levels in PKU patients.

At a glance

Mechanism of action

Pegvaliase-pqpz is a modified enzyme that breaks down phenylalanine into ammonia and trans-cinnamic acid. This process mimics the function of the missing or deficient phenylalanine hydroxylase enzyme, thereby lowering blood phenylalanine levels in patients with PKU.

Approved indications

• Phenylketonuria (PKU) Management

Boxed warnings

• WARNING: ANAPHYLAXIS Anaphylaxis has been reported after administration of PALYNZIQ and may occur at any time during treatment [see Warnings and Precautions (5.1) ] . Administer the initial dose of PALYNZIQ under the supervision of a healthcare provider equipped to manage anaphylaxis, and closely observe patients for at least 60 minutes following injection. Prior to self-injection, confirm patient competency with self-administration, and patient's and observer's (if applicable) ability to recognize signs and symptoms of anaphylaxis and administer epinephrine, if needed [see Dosage and Administration (2.5) ] . Consider having an adult observer for patients who may need assistance in recognizing and managing anaphylaxis during PALYNZIQ treatment. If an adult observer is needed, the observer should be present during and for at least 60 minutes after PALYNZIQ administration, should be able to administer epinephrine, and call for emergency medical support upon its use [see Warnings and Precautions (5.1) ] . Prescribe epinephrine to all patients treated with PALYNZIQ. Prior to the first dose, instruct the patient and observer (if applicable) how to recognize the signs and symptoms of anaphylaxis, how to properly administer epinephrine, and to seek immediate medical care upon its use. Instruct patients to carry epinephrine with them at all times during treatment with PALYNZIQ [see Dosage and Administration (2.5) and Warnings and Precautions (5.1) ] . Consider the risks and benefits of readministering PALYNZIQ following an episode of anaphylaxis. If the decision is made to readminister PALYNZIQ, readminister the first dose under the supervision of a healthcare provider equipped to manage anaphylaxis and closely observe the patient for at least 60 minutes following the dose [see Dosage and Administration (2.5) and Warnings and Precautions (5.1) ] . Because of the risk of anaphylaxis, PALYNZIQ is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the PALYNZIQ REMS [see Warnings and Precautions (5.2) ]. WARNING: ANAPHYLAXIS See full prescribing information for complete boxed warning. Anaphylaxis has been reported after administration of PALYNZIQ and may occur at any time during treatment. ( 5.1 ) Administer the initial dose of PALYNZIQ under the supervision of a healthcare provider equipped to manage anaphylaxis, and closely observe patients for at least 60 minutes following injection. Prior to self-injection, confirm patient competency with self-administration, and patient's and observer's (if applicable) ability to recognize signs and symptoms of anaphylaxis and to administer epinephrine, if needed. ( 2.5 ) Prescribe epinephrine. Prior to first dose, instruct the patient and observer (if applicable) on its appropriate use. Instruct the patient to seek immediate medical care upon its use. Instruct patients to carry epinephrine with them at all times during PALYNZIQ treatment. ( 2.5 , 5.1 ) PALYNZIQ is available only through a restricted program called the PALYNZIQ REMS. ( 5.2 )

Common side effects

• injection site reactions
• arthralgia
• hypersensitivity reactions
• headache
• generalized skin reactions lasting at least 14 days
• nausea
• abdominal pain
• vomiting
• cough
• oropharyngeal pain
• pruritus
• diarrhea

Drug interactions

• medroxyprogesterone acetate injectable suspension

Key clinical trials

• A Long-term, Post-marketing Safety Study of Palynziq in Patients With PKU (PALace)
• A Global, Multicenter Study to Assess Maternal, Fetal and Infant Outcomes of Exposure to Palynziq® (Pegvaliase) During Pregnancy and Breastfeeding
• A Long Term, Post-marketing Study of Immune Response in Patients Receiving Palynziq Treatment for PKU (PALisade)
• Immune Modulation During Palynziq® Treatment in Adults (IMPALA) (PHASE4)
• Nutritional Impacts of Palynziq on Patients With Phenylketonuria (PKU)
• Preliminary Study of Brain Effects of Palynziq-Related Changes in Phenylalanine in Individuals With PKU
• Study to Evaluate the Safety and Efficacy of Pegvaliase in Adolescents (Ages 12-17) With Phenylketonuria (PHASE3)
• Rapid Drug Desensitization Study in Adults Experiencing Hypersensitivity Reactions to Palynziq (PHASE4)

Primary sources

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Competitive intelligence

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