Public health company The US Food and Drug Administration revealed on Thursday that it has authorised Palynziq (pegvaliase-pqpz) for adults with the rare and serious genetic disease, phenylketonuria (PKU).

In addition, the US FDA has granted approval of Palynziq to BioMarin Pharmaceutical Inc.

The patients with PKU are born with an inability to break down phenylalanine (Phe), an amino acid present in protein-containing foods and high-intensity sweeteners used in foods and beverages. If untreated, PKU can cause chronic intellectual, neurodevelopmental and psychiatric disabilities.

Palynziq is a novel enzyme therapy for adult PKU patients who have uncontrolled blood Phe concentrations on current treatment. Its safety and efficacy was based on the company's two clinical trials in adult patients with PKU with blood phenylalanine concentrations greater than 600 µmol/l.

Additionally, the first trial was a randomized, open-label trial in patients treated with increasing doses of Palynziq administered as a subcutaneous injection up to a target dose of either 20mg once daily or 40mg once daily. The second trial was an eight week, placebo-controlled, randomized withdrawal trial in patients who were previously treated with Palynziq.

According to the company, the patients treated with Palynziq achieved statistically significant reductions in blood phenylalanine concentrations from their pre-treatment baseline blood Phe concentrations.