Global pharma giant Novartis has gained FDA approval for its groundbreaking gene therapy for older children and adults with spinal muscular atrophy (SMA).

 

The green light for Itvisma (onasemnogene abeparvovec-brve) for children aged two and older, teens, and adults with SMA caused by a confirmed mutation in the SMN1 gene, marks the first and only gene replacement therapy available for this broad SMA population.

 

Itvisma is a one-time, fixed-dose therapy designed to tackle the genetic root cause of SMA, improving motor function without the need for dose adjustments by age or weight. By replacing the missing or defective SMN1 gene, the therapy offers potential relief from the lifelong regimen required by existing treatments.

 

“The FDA’s approval of intrathecal onasemnogene abeparvovec is a game-changing advance, expanding the use of transformational gene replacement therapy for SMA across age groups,” said John W Day, Professor of Neurology and Pediatrics at Stanford University School of Medicine. “This achievement is not only a significant step forward for SMA – it also signals new possibilities for the broader field of neurological disorders and genetic medicine.”

 

The approval follows results from the Phase III STEER study and the open-label Phase IIIb STRENGTH study, which showed significant improvements in motor function and stabilization of abilities rarely seen in untreated patients. 

 

Effects were maintained for 52 weeks, and the safety profile was consistent across both studies. The most common adverse events included upper respiratory infections, fever, and vomiting. Data were presented at the 2025 Muscular Dystrophy Association Clinical and Scientific Conference.

 

"This new route of administration for a single dose of gene replacement therapy can mean so much more than what is measured by numbers on a functional motor scale – it could mean greater independence and freedom in activities of daily life,” said Kenneth Hobby, President, Cure SMA. 

 

“The SMA disease landscape has dramatically changed over the last six years, when the first gene therapy was approved. This is another welcome advancement, and it represents real progress in expanding access for many older patients and addressing the unmet needs that remain in our community.”

 

SMA is a rare genetic neuromuscular disease caused by a missing or mutated SMN1 gene, leading to progressive muscle weakness and loss of motor function. While treatments exist, many older children, teens, and adults still face unmet needs in preserving muscle strength.

 

"After redefining SMA care with the first gene replacement therapy for this challenging disease, we can now help address unmet needs across an even broader SMA population with the approval of Itvisma," said Victor Bultó, President, Novartis US. 

 

“We are proud to support the SMA community by empowering patients of all ages through our innovative, one-time therapies, offering the potential to reduce the burden that comes with chronic treatment.”

 

Itvisma will be available in the US from December, offering a single intrathecal injection that delivers a functional SMN1 gene to support sustained motor function and reduce dependence on chronic therapies.