Pegvaliase is a medication used to treat phenylketonuria (PKU), a rare genetic condition that causes an amino acid called phenylalanine to build up in the body. This medication is given as an injection under the skin (subcutaneous injection). It works by helping the body break down phenylalanine, which can help reduce its levels in the blood. This treatment is being studied as an alternative or supplement to the traditional dietary management of PKU in adolescent patients.

Diet-only control represents the traditional treatment approach for PKU, which involves following a strict diet that limits the intake of foods containing phenylalanine. This typically means avoiding foods high in protein such as meat, fish, eggs, dairy products, nuts, and some grains.

Phenylketonuria (PKU) – A genetic disorder that affects the body’s ability to process an amino acid called phenylalanine, which is found in many foods containing protein. When a person has PKU, phenylalanine builds up in the body because an enzyme needed to break it down is missing or not working properly. The condition is present from birth and is inherited in an autosomal recessive pattern, meaning both parents must pass on the defective gene. Without dietary management, phenylalanine accumulates in the blood and can lead to various developmental issues. The disorder affects how the body processes protein and requires careful monitoring of protein intake through diet.