A 10-Year Observational Study on Immune and Inflammatory Effects of Long-Term Palynziq Pegvaliase Treatment in People With Phenylketonuria PKU in the United States

What this Trial Is About

Researchers are conducting a 10-year multi-center, prospective, longitudinal study in the United States to observe immunologic, inflammatory, and laboratory changes in people with phenylketonuria PKU who are treated with Palynziq pegvaliase. The study includes both new users starting pegvaliase within 30 days after enrolling in a related study 165-501 and those who have already been receiving the treatment before enrollment. The goal is to understand long-term immune and inflammatory responses to this treatment. Participants must already be enrolled in the 165-501 study to join this study. They will provide blood samples before dosing every three months for the first three years, then every six months for the remaining study period. Additional blood samples may be taken during safety events as defined in the related 165-501 study protocol, and standard care blood draws are also incorporated. Blood tests will measure phenylalanine levels and various immune and inflammatory markers, which will be processed centrally. During the study, data from this observational study will be combined with data from the 165-501 study to reduce duplicate reporting and lessen the burden on study sites. Participants may withdraw from this study while continuing in the 165-501 study, but not vice versa, to ensure safety monitoring. The research team will evaluate immune and inflammatory responses over up to 10 years of treatment, tracking changes through blood tests and clinical data collection for a comprehensive understanding of long-term effects.

A Long Term, Post-marketing Study of Immune Response in Patients Receiving Palynziq Treatment for PKU (PALisade)