The U.S. Food & Drug Administration (FDA) has accepted a filing application and will give priority review to a new drug to treat spinal muscular atrophy (SMA) Type 1.

In a news announcement, Cure SMA described the drug — AVXS-101, by Novartis — as “an investigational gene replacement therapy for the treatment of SMA Type 1.” The drug, now known as Zolgensma, “is designed to address the genetic root cause of SMA Type 1, a deadly neuromuscular disease with limited treatment options.”

Intravenous, One-Time Delivery

Cure SMA added that regulatory action related to the priority review is expected in May 2019. The filing with the FDA is for an intravenous delivery of the gene therapy. In clinical trials, study participants were infants less than 9 months old who had SMA Type 1.

Children with SMA Type 1 have a defective or missing SMN1 gene, and “rapidly lose the motor neurons responsible for muscle functions such as breathing, swallowing, speaking and walking.” Without treatment, children with this most severe form of SMA usually die by the age of 2.

Zolgensma is described as a single, one-time infusion that replaces the missing or defective SMN1 gene with a working version of the gene. The replacement improves “motor neuron function and survival,” Cure SMA said.

David Lennon, President of AveXis, said, “As a one-time infusion that addresses the genetic root cause of SMA without the need for repeat dosing, Zolgensma represents a potentially significant therapeutic advance for these patients and their families.”

AveXis, the company that created Zolgensma, was acquired by Novartis in 2018.

New Milestones Achieved

In the clinical trial, 15 children who had SMA Type 1 were dosed with Zolgensma. At 24 months, all 15 study participants were “alive and without the need for permanent ventilation,” Cure SMA reported. And 92 percent of the study participants could sit unassisted for more than five seconds, “a milestone never achieved in the natural history of SMA Type 1.”

Cure SMA is a national organization dedicated to SMA awareness, support for families living with SMA, and research to develop treatments for SMA. The organization’s annual conference — a combined event for families and researchers — takes place in June in Anaheim, Calif. For more information on the event, visit www.curesma.org.

Spinal muscular atrophy is the number-one genetic cause of death for young children.