FDA Expands Approval of PALYNZIQ for Adolescents with Phenylketonuria (PKU)

The U.S. Food and Drug Administration (FDA) has approved a supplemental Biologics License Application (sBLA) for BioMarin Pharmaceutical’s PALYNZIQ® (pegvaliase-pqpz), extending its utilize to include pediatric patients 12 years of age and older with phenylketonuria (PKU). This approval marks a significant advancement in the treatment of PKU, offering a new option for adolescents who often face challenges managing the condition during a critical period of development.

Understanding Phenylketonuria (PKU)

Phenylketonuria (PKU) is a rare, inherited metabolic disorder that affects the body’s ability to break down phenylalanine (Phe), an amino acid found in protein. If left untreated, PKU can lead to intellectual disability, seizures, and other neurological problems. Management typically involves a strict, lifelong diet limiting Phe intake. Mayo Clinic

PALYNZIQ: A Novel Enzyme Substitution Therapy

PALYNZIQ is the first enzyme substitution therapy approved for PKU. It works by providing the enzyme that individuals with PKU lack, helping to lower blood Phe concentrations. Unlike traditional PKU management, PALYNZIQ may allow for a less restrictive diet. BioMarin

The Importance of Treatment During Adolescence

Adolescence presents unique challenges for individuals with PKU. Increasing independence, academic pressures, and social factors can make it difficult to adhere to the strict dietary restrictions required for PKU management. Poor blood Phe control during this period can have adverse neurocognitive consequences. “Adolescence is a period of increasing independence and academic demands, and represents a particularly challenging time for individuals with PKU,” said Dr. Stephanie Sacharow, Director, Dr. Harvey Levy Program for PKU and Related Conditions, Boston Children’s Hospital. BioMarin

Dr. Sacharow further noted that treatment adherence is often more successful in teens while they are living at home with family support, and this approval extends this therapeutic option to adolescents who may benefit most. The Pharma Letter

Clinical Evidence: The PEGASUS Study

The FDA approval is based on data from the PEGASUS study, a Phase 3 clinical trial evaluating the efficacy and safety of PALYNZIQ compared to diet alone in adolescents with PKU and uncontrolled blood Phe levels. BioMarin

Future Directions

BioMarin is also seeking approval from the European Medicines Agency (EMA) to expand PALYNZIQ treatment to include adolescents as young as 12 in the European Union. Nasdaq

This expanded approval of PALYNZIQ represents a significant step forward in providing more effective and convenient treatment options for adolescents with PKU, potentially improving their quality of life and long-term outcomes.