pegvaliase

Pegvaliase is an enzyme replacement therapy used to treat phenylketonuria (PKU). It is a pegylated form of phenylalanine ammonia-lyase (PAL) that metabolizes phenylalanine in the blood, converting it to trans-cinnamate and ammonia. By lowering circulating phenylalanine levels, pegvaliase aims to reduce the dietary restrictions typically required to manage PKU.

Indication and use: Pegvaliase is indicated for adults with PKU who have inadequate control of blood phenylalanine levels on a low-phenylalanine diet or who cannot maintain such a diet. Its use in children is not generally approved, and pediatric data are limited. Treatment decisions are individualized and guided by clinician assessment of phenylalanine levels, dietary tolerance, and tolerability.

Administration and dosing: The therapy is given as subcutaneous injections and is intended for long-term treatment. Dosing requires gradual titration to minimize the risk of hypersensitivity reactions, including anaphylaxis. A personalized dosing plan is established by the prescriber, with regular monitoring of phenylalanine levels and adverse events. Patients are educated to recognize early signs of allergic reactions and to seek prompt medical attention if needed.

Efficacy and safety: Pegvaliase can significantly reduce blood phenylalanine concentrations, enabling less restrictive diets for some patients. The regimen carries a boxed warning for anaphylaxis and carries risks of injection reactions, hypersensitivity, and immune responses that may affect efficacy. Adverse events are monitored closely, and patients may require ongoing assessment of antibody development against PAL.

Regulatory status: In some jurisdictions, pegvaliase (brand Palynziq) has regulatory approval for adult PKU. Availability and labeling vary by country.