FDA Approves New Treatment for Spinal Muscular Atrophy

The FDA has approved a new treatment for spinal muscular atrophy (SMA) in adult and pediatric patients 2 years of age or older with a “confirmed mutation in the survival motor neuron 1 (SMN1) gene.”

The new treatment, Itvisma, is an “adeno-associated virus (AAV) vector-based gene therapy.” Clinical trials for the treatment were successful, as were efficacy findings from another treatment (Zolgensma) that contains the same active ingredient in an intravenous formulation. Zolgensma is administered intravenously, but Itvisma is administered “directly to the central nervous system via a single intrathecal injection independent of patient weight, which expands treatment options available to patients with SMA.”

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.” Before effective treatment was available, SMA was one of the leading causes of infant mortality due to genetic disease in the U.S.

The direct administration of Itvisma into the “cerebrospinal fluid surrounding the spinal cord…allows for delivery to motor neurons with a lower dose of vector, without the need to adjust for the patient’s body weight. This provides a treatment with rapid onset and direct targeting of the genetic root cause of SMA.”