A Study to Learn About the Safety and Effects of the Study Drug PRX-102 in Children and Adolescents With Fabry Disease

This study aims to learn how safe pegunigalsidase alfa (PRX-102 for short) is and how it works at treating Fabry disease in children and adolescents. PRX-102 is an enzyme replacement therapy (ERT), meaning it acts like a natural enzyme. PRX-102 is given through a needle placed in a vein (intravenous infusion) every two weeks. The main questions this study aims to answer are: * Which is the safest and most effective dose to be given to children and adolescents. * Which effects PRX-102 has on signs and symptoms of Fabry disease (e.g. renal and cardiac function, pain, gastrointestinal symptoms) 20 to 22 boys and girls with Fabry disease between the ages of 2 and 17 will be part of this study. There will be three age cohorts, with children aged 2 to 7 years included (enrolled) in Cohort A, children aged 8 to 12 years in Cohort B, and adolescents aged 13 to less than 18 years in Cohort C. The study is divided into three parts, or "stages": * A dose-finding stage (Stage I). In this stage, researchers will determine the dose for children. * A confirmatory stage (Stage II). In this part, researchers will learn about the safety and efficacy of PRX-102. * and an optional extension stage (Stage III) will continue until the study drug becomes commercially available or the Sponsor chooses to end this study. PRX-102 will be given at the study visits, which will occur at least every two weeks. Tests for verifying the study drug's safety and efficacy and determining the dose will also be conducted at different time points throughout the study (not all tests will be done at all visits). These tests may include a review of any health problems and medications the participants have had or taken since the last visit; a physical examination; ECG; ultrasound of the heart; questionnaires that evaluate the nature and severity of Fabry disease symptoms, quality of life and pain; a collection of blood and urine samples for standard safety tests, to analyse the severity of Fabry disease and to see how the drug is behaving and how long it remains active in the body (this involves taking multiple blood samples over several days with the first sample taken just before the start of the PRX-102 infusion and the last one taken just before the start of the next PRX-102 at the next visit).