Passage Bio, Inc. announced that the first patient with early infantile Krabbe disease has received PBKR03, an adeno-associated virus (AAV)-delivery gene therapy, in its global Phase 1/2 clinical trial, GALax-C. Krabbe disease is a rare pediatric lysosomal storage disorder caused by mutations in the GALC gene, which encodes galactosylceramidase, an enzyme that breaks down galactosylceramide and psychosine. Without adequate levels of galactosylceramidase, psychosine accumulates, causing widespread death of myelin-producing cells and progressive damage to nerves in both the brain and peripheral tissues of affected children. This is characterized in children by loss of acquired milestones, staring episodes, apnea, peripheral neuropathy, severe weakness, unresponsiveness to stimuli, seizures, blindness, and deafness.

Life expectancy for early infantile Krabbe disease, the most severe form, is two years. The U.S. Food and Drug Administration (FDA) has granted PBKR03 Fast Track, Orphan Drug, and Rare Pediatric Disease designations. PBKR03 has also received an Orphan designation from the European Commission.