BioMarin Announces Positive Pivotal Phase 3 Data for PALYNZIQ® (pegvaliase-pqpz) in Adolescents with Phenylketonuria at 15th International Congress of Inborn Errors of Metabolism

Core Insights - The Phase 3 PEGASUS study shows a 49.7% reduction in mean blood phenylalanine (Phe) levels in adolescents aged 12-17 treated with PALYNZIQ compared to diet alone [1][2][3] - BioMarin plans to submit the PEGASUS study data to global health authorities in the second half of 2025 to expand PALYNZIQ's indication to include adolescents [1][4] Study Details - The PEGASUS study involved 55 adolescents, with 36 receiving PALYNZIQ and 19 on diet alone, showing significant efficacy in lowering blood Phe levels [2][8] - At baseline, the mean age of participants was 14.3 years, with a mean blood Phe level of 1026.4 µmol/L; nearly half had levels above 1000 µmol/L [2] - After 72 weeks, 45.2% of participants in the PALYNZIQ group achieved a reduction of 50% or more in blood Phe concentrations [2][3] Efficacy Results - The mean percentage change in blood Phe concentration from baseline for the PALYNZIQ group was -49.7%, while the diet-only group showed a negligible change of -0.3% [3] - Significant achievements in blood Phe levels included 51.6% of PALYNZIQ participants reaching levels below 600 µmol/L, and 38.7% below 360 µmol/L [3] Safety Profile - The safety profile of PALYNZIQ in adolescents was consistent with its known profile in adults, with 5.6% of adverse events being serious [3][4] - The ongoing extension phase of the PEGASUS trial will continue to evaluate long-term safety and efficacy [3][4] Company Commitment - BioMarin has been dedicated to advancing treatments for PKU for over two decades and aims to provide effective solutions for adolescents transitioning to adulthood [4][12] - PALYNZIQ is the first enzyme substitution therapy approved for adults with PKU, and the company seeks to expand its use to younger populations [4][10]