A Non-Interventional Interview Study of Phenylketonuria (PKU) Adults

Clinical studies have suggested that treatment with pegvaliase results in lowering of blood Phenylalanine levels in adults with Phenylketonuria (PKU). Because these individuals often exhibit inattention and mood difficulties, and blood Phe concentration affects cognition and mood, life-long blood Phe control with pegvaliase may improve cognitive abilities and emotional and mental health in patients with PKU. In order to adequately quantify potential pegvaliase treatment impact on cognition and mood, it is necessary to employ clinical outcome assessments (COAs) that are fit for purpose and that comprehensively address concepts important, relevant, and meaningful to PKU patients. This is an observational study to identify symptom, function, and health-related quality of life (HRQoL) concepts of interest (COIs) to patients with PKU and to seek additional patient, observer, and expert input on the appropriateness of concepts of BioMarin's proposed COAs for use in future efficacy trials in PKU.