ARSA and metachromatic leukodystrophy: In contrast, the result of a phase I/II trial (OTL-200/NCT01560182) published at the beginning of this year showed the treatment with arsa-cel (atidarsagene autotemcel, LibmeldyTM,Orchard, shown in Table 1), an ex vivo gene therapy containing autologous HSCs transduced with SIN-lentiviral vector encoding human ARSA cDNA, resulted in sustained, clinically relevant benefits in children with early-onset MLD [148].