Ethical Approval
This study was carried out in accordance with the Declaration of Helsinki and approved by the local MRB of all study centers; the Medical Ethics Committee of the University Medical Center Utrecht, Utrecht, the Netherlands (NL55788.041.15); the ethics committee of University Regensburg, Germany (18–1034–101); Clinical Research Ethics Committee of the Basque Country, Spain (PI2015075 (SO)); National Medical Ethics Committee, Slovenia (0120–569/2017/4)). The SysPharmPediA study was registered at Clinicaltrials.gov with the identifier of NCT04865575. All participants/parents gave their informed consent.