United States, Nov. 24 -- The U.S. Food and Drug Administration approved Itvisma (onasemnogene abeparvovec-brve) for the treatment of spinal muscular atrophy (SMA) in adult and pediatric patients 2 years of age and older with confirmed mutation in the survival motor neuron 1 (SMN1) gene. Itvisma is an adeno-associated virus (AAV) vector-based gene therapy. SMA is an autosomal-recessive neurodegenerative disorder caused by mutations in the SMN1 gene, characterized by irreversible and progressive motor neuron loss, leading to progressive muscle atrophy and weakness, and subsequent paralysis and death in the most severe cases. SMA has an incidence of approximately 4-10 per 10,000 live births. Prior to the availability of effective treatment, S...