Novartis has received approval from the US Food and Drug Administration (FDA) for the Itvisma (onasemnogene abeparvovec-brve) gene replacement therapy to treat spinal muscular atrophy (SMA).

This therapy is intended for children aged two years and above, teens and adults with SMA who have a confirmed mutation in the survival motor neuron 1 (SMN1) gene.

It is a one-time fixed dose therapy that targets the genetic cause of SMA and replaces the SMN1 gene to improve motor function without requiring dosage adjustment by age or body weight.

The FDA approval is supported by findings from the open-label Phase IIIb STRENGTH study and the Phase III STEER trial, which demonstrated significant improvements in stabilisation and motor function over 52 weeks.

Both studies showed a consistent safety profile.

SMA is a rare genetic neuromuscular disorder and is caused by a defective or missing SMN1 gene, which is responsible for producing majority of the SMN protein necessary for muscle function.

Novartis US president Victor Bultó said: “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.

“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 is designed to provide a functional copy of the human SMN1 gene via a single, one-time intrathecal injection to sustain SMN protein expression and improve motor function. It is set to be released in the US in December 2025.

In October 2025, Novartis signed an agreement for the acquisition of all outstanding shares of US-based Avidity Biosciences for $12bn in cash on a fully diluted basis.