FDA Approves Novartis’s AAV Gene Therapy for Broad Spinal Muscular Atrophy Population

BASEL, Switzerland – November 25, 2025– Novartis announced that the U.S. Food and Drug Administration (FDA) has approved Itvisma® (onasemnogene abeparvovec-brve) for the treatment of children aged two years and older, teens, and adults living with Spinal Muscular Atrophy (SMA) who have a confirmed mutation in the survival motor neuron 1 (SMN1) gene.

This marks Itvisma as the first and only gene replacement therapy using an adeno-associated virus (AAV) vector available for this broad population. The one-time, fixed-dose therapy is uniquely designed to address the genetic root cause of SMA by providing a functional copy of the human SMN1 gene. This approach aims to reduce the need for chronically administered treatment associated with other available therapies.

“The FDA’s approval of intrathecal onasemnogene abeparvovec is a game-changing advance, expanding the use of transformational AAV gene replacement therapy for SMA across age groups,” said Dr. John W. Day, Professor of Neurology and Pediatrics at Stanford University School of Medicine.

Phase III Data Shows Motor Function Improvements

The approval is supported by robust data from the registrational Phase III STEER study and the open-label Phase IIIb STRENGTH study.

• Efficacy: Itvisma demonstrated statistically significant improvements in motor function and stabilization of motor abilities, effects typically not seen in the natural history of the disease, with benefits sustained over 52 weeks of follow-up. This is achieved by the AAV delivery of the SMN1 gene, ensuring sustained SMN protein expression.

• Safety: The AAV gene therapy demonstrated a consistent safety profile across both studies. Common adverse events included upper respiratory tract infection, pyrexia, and vomiting.

SMA is a rare, genetic neuromuscular disease caused by a missing or mutated SMN1 gene, which is essential for producing the SMN protein needed for muscle function.

Transforming Care with One-Time AAV Therapy

Itvisma utilizes an adeno-associated virus 9 (AAV9) vector, delivered via a single, one-time intrathecal injection, to target motor neurons.

“This new route of administration for a single dose of AAV 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.

Novartis holds exclusive, worldwide licenses covering the intravenous and intrathecal delivery of the AAV9 gene replacement therapy for SMA, including agreements with Nationwide Children’s Hospital and REGENXBIO for their respective AAV vector intellectual property.