Products
Pegvaliase was approved in the United States in 2018 as an injectable (Palynziq). The drug is not yet registered in many countries.
Structure and properties
Pegvaliase is a phenylalanine-metabolizing enzyme consisting of recombinant phenylalanine ammonia lyase conjugated to -hydroxysuccinimide methoxy polyethylene glycol. The gene of the enzyme is derived from cyanobacterium . According to the literature, pegylation increases stability and reduces immunogenicity.
Effects
The enzyme pegvaliase metabolizes the amino acid phenylalanine to ammonia and trans-cinnamic acid, which are biotransformed by the liver and excreted in the urine. Pegvaliase serves as a replacement for the endogenous enzyme phenylalanine hydroxylase (PAH), which is absent in the disease.
Indications
For the treatment of phenylketonuria with uncontrolled blood levels greater than 600 µmol/L with existing therapy.
Dosage
According to the SmPC. The drug is injected as a subcutaneous injection.
Contraindications
For complete precautions, see the drug label.
Adverse effects
The most common possible adverse effects include injection site reactions, joint pain, hypersensitivity reactions, headache, generalized skin reactions, pruritus, nausea, abdominal pain, oropharyngeal pain, vomiting, cough, diarrhea, and fatigue. Anaphylaxis is relatively common.
