Passage Bio, Inc. announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for PBML04, an adeno-associated virus (AAV)-delivery gene therapy that is being studied for the treatment of Metachromatic Leukodystrophy (MLD). MLD is a rare, fatal, pediatric, lysosomal storage disease that currently has limited available treatment options. MLD is a fatal inherited disease that is caused by mutations in the arylsulfatase-A (ARSA) gene which reduces enzyme activity, leading to progressive build-up of toxic sulfatides in the central and peripheral nervous system.

Targeting infantile-onset MLD, which is characterized by progressive muscle weakness, rigidity, gait disorder, developmental delays and is typically fatal by five years of age. The estimated worldwide incidence of MLD is approximately 1 in 100,000 live births. The Phase 1 clinical trial will utilize intra-cisterna magna (ICM) administration to deliver an AAVhu68 capsid to express ARSA and potentially address both central nervous system and peripheral manifestations of this devastating disease.