Neutralizing Antibody Seroprevalence Study With a Retrospective Component in Participants With Late-Onset Pompe Disease

The purpose of this study is to obtain information pertaining to the occurrence of antibodies to investigational SPK-3006 capsid and GAA, GAA activity and GAA antigen levels in the usual care setting of Late-Onset Pompe Disease (LOPD) participants on an enzyme replacement regimen. Additionally, a careful evaluation of laboratory and functional testing in patients with LOPD may provide information to better understand the disease features and better drive the design of a future interventional investigational gene therapy trial. An understanding of the underlying status of liver and muscle health in individuals with LOPD may also inform best surveillance during the conduct of gene therapy trials.