Summary: The purpose of this study is to determine if rapid drug desensitization (RDD) to Palynziq will improve drug tolerability and treatment persistence in adult patients on commercial Palynziq experiencing hypersensitivity reactions (HSRs) leading to treatment interruption or reduction of dose or dosing frequency. See Section 10.8 for full list of HSR preferred terms. Study details include: * Study dur...

Summary: Phenylketonuria (PKU) is an inherited metabolic disorder that impairs the metabolism of the essential amino acid phenylalanine (Phe). Without stringent dietary control, Phe accumulates in the blood and brain of PKU patients, leading to severe cognitive deficits. Achieving metabolic control, defined as blood Phe levels within the range of 120-360 μmol/L, has been a significant challenge for PKU pat...

Summary: This is a 10-year multi-center, prospective, longitudinal, single arm study evaluating immunologic, inflammatory and laboratory parameters associated with long-term Palynziq treatment in subjects with phenylketonuria (PKU) in the United States (US). Subjects in the US for whom a clinical decision has been made that they will receive pegvaliase to treat their PKU within 30 days following the date o...

Summary: This is a 10-year multi-center, global, observational study to further characterize the safety profile of pegvaliase, including hypersensitivity reactions, long-term safety and tolerability, and the effectiveness of the additional risk minimization measures (aRMMs) (European Union (EU) only) in subjects receiving pegvaliase for the treatment of PKU. Subjects for whom a clinical decision has been m...

Summary: This is a Phase 4 observational study designed to assess the impact of Palynziq ® (pegvaliase) treatment in pregnant women with PKU and on their offspring who were exposed to pegvaliase at any time during pregnancy and breastfeeding.