Biomarin’s Palynziq has been approved as the first enzyme therapy to treat the rare brain-threatening genetic disease phenylketonuria (PKU) in adults in the US.

Palynziq (pegvaliase-pqpz), a PEGylated recombinant phenylalanine ammonia lyase enzyme, it the only treatment to target the underlying cause of PKU by helping the body restore its ability to break down Phe, an amino acid that is found in all forms of protein.

High levels of Phe become toxic to the brain and can cause serious neurological and neuropsychiatric-related issues, affecting how a person thinks, feels, and acts.

Patients with PKU need life-long management, including sticking to a severely restrictive daily diet of medical foods and formula that avoids the ingestion of Phe, which is present in most foods.

The approval of Palynziq “marks an important milestone” for adults living with the condition, “who will now have access to an effective new treatment option for controlling their blood Phe,” the firm noted.

"Palynziq has the potential to be a game-changing therapy for adults in the PKU community who have struggled throughout their lives to control their Phe levels, despite rigorous management," said Christine Brown, MS, executive director of the National PKU Alliance.

The therapy is also currently under review in Europe.