San Rafael, California — October 30, 2025 — BioMarin Pharmaceutical Inc. announced that the U.S. Food and Drug Administration (FDA) has accepted the Supplemental Biologics License Application (sBLA) for PALYNZIQ® (pegvaliase-pqpz), granting Priority Review to expand its use for adolescents aged 12 to 17 living with phenylketonuria (PKU). This regulatory milestone extends access to a first-in-class enzyme substitution therapy already approved for adults, offering new treatment hope for younger patients with uncontrolled blood phenylalanine levels.
Science Significance
PALYNZIQ, a PEGylated recombinant phenylalanine ammonia lyase enzyme, represents a landmark in enzyme substitution therapy for PKU — a rare metabolic disorder caused by phenylalanine hydroxylase deficiency. By enzymatically degrading excess phenylalanine, PALYNZIQ enables dietary freedom and metabolic control that traditional dietary management cannot achieve. Expanding its use to adolescents demonstrates the growing clinical confidence in pegvaliase’s long-term efficacy and safety, supported by Phase 3 PEGASUS data showing sustained reductions in blood phenylalanine levels and improved quality of life across age groups.
Regulatory Significance
The FDA’s Priority Review designation underscores the therapy’s potential to address an unmet medical need in pediatric metabolic disease management. PALYNZIQ carries a boxed warning for anaphylaxis and is distributed through a Risk Evaluation and Mitigation Strategy (REMS) program to ensure safe patient monitoring. This review also highlights the agency’s continued focus on biologic lifecycle management, where label expansions are supported by post-marketing safety data and pharmacovigilance infrastructure. The sBLA evaluation will likely examine clinical consistency, immunogenicity profiles, and manufacturing controls, reaffirming the link between Good Clinical Practice (GCP) and Good Manufacturing Practice (GMP) compliance in biologic submissions.
Business Significance
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For BioMarin, this milestone strengthens its biologic portfolio and underscores its leadership in rare disease therapeutics. PALYNZIQ’s adolescent indication may broaden market access and reinforce the company’s revenue pipeline alongside other rare disease assets. The company’s integrated approach—spanning clinical research, regulatory strategy, and global supply chain excellence—positions BioMarin as a key innovator in precision biologic therapies. A successful review outcome could accelerate international submissions, expanding global access to BioMarin’s proprietary enzyme therapy platform.
Patients’ Significance
For adolescents and their families, this development offers a pathway toward normalizing daily life in PKU management. By reducing reliance on strict dietary control and enabling improved metabolic stability, PALYNZIQ could significantly enhance psychosocial well-being and long-term health outcomes. The therapy represents a tangible step toward personalized metabolic medicine, ensuring earlier intervention and continuity of care from adolescence into adulthood
Policy Significance
The FDA’s expedited review reflects evolving policy priorities in rare disease care, emphasizing accelerated pathways for therapies addressing chronic metabolic conditions. It highlights regulators’ commitment to patient-centric innovation and the importance of post-approval safety frameworks for biologics. The PALYNZIQ review could also serve as a model for biologic lifecycle regulation, demonstrating how consistent quality data, real-world evidence, and pharmacovigilance can support safe label extensions across demographics.
As BioMarin advances its PALYNZIQ expansion, the company continues to shape the biopharmaceutical landscape for inherited metabolic disorders. The FDA’s Priority Review not only reinforces PALYNZIQ’s clinical importance but also reflects broader industry confidence in safe, compliant, and scalable biologic therapies. If approved, this label expansion would mark another step toward a comprehensive, age-inclusive approach to PKU management, aligning science, regulation, and patient care under the shared banner of biopharma innovation.
Source: BioMarin Pharmaceutical Inc. press release
