Core Viewpoint - BioMarin Pharmaceutical Inc. has received FDA acceptance for Priority Review of its supplemental Biologics License Application (sBLA) for PALYNZIQ, aimed at expanding treatment for adolescents aged 12-17 with phenylketonuria (PKU), with a target action date set for February 28, 2026 [1][2][25]. Group 1: Product and Study Information - PALYNZIQ (pegvaliase-pqpz) is the first enzyme substitution therapy approved for adults with PKU and is now being evaluated for adolescents [3][5]. - The sBLA is based on the Phase 3 PEGASUS study, which demonstrated significant blood phenylalanine (Phe) lowering compared to diet alone in adolescents aged 12-17 [1][3][4]. - The PEGASUS study involved 55 adolescents and assessed safety and efficacy, with primary endpoints focusing on blood Phe concentration changes [4][10]. Group 2: Market and Regulatory Context - BioMarin aims to share data with the European Medicines Agency to expand PALYNZIQ treatment to adolescents as young as 12 in the EU [2][25]. - The company has a strong track record in the PKU community, having led scientific progress for over two decades [2][25]. - PALYNZIQ is currently approved for PKU treatment in more than 35 countries worldwide [6]. Group 3: Patient Needs and Treatment Goals - There is a significant need for better treatment options for adolescents and young adults with PKU to achieve meaningful reductions in blood Phe levels while allowing greater dietary freedom [2][10]. - The results from the PEGASUS trial indicate that PALYNZIQ can help adolescents reach guideline-recommended and even normal Phe levels while consuming more protein from whole foods [2][10].