Gene Replacement Therapy Clinical Trial for Participants With Spinal Muscular Atrophy Type 1

Phase 3, open-label, single-arm, single-dose, study of onasemnogene abeparvovec-xioi (gene replacement therapy) in participants with spinal muscular atrophy (SMA) Type 1 who meet enrollment criteria and are genetically defined by nonfunctional survival motor neuron 1 gene (SMN1) with 1 or 2 copies of survival motor neuron 2 gene (SMN2). Fifteen (15) participants \< 6 months (\< 180 days) of age at the time of gene replacement therapy (Day 1) will be enrolled.