• 25 Nov 2025
• Admin
• News Article

FDA Approves Itvisma: A Breakthrough Gene Therapy for SMA Across All Ages

The SMA treatment landscape just changed again — and this time, the impact is massive.
Novartis has secured FDA approval for Itvisma® (onasemnogene abeparvovec-brve), the first and only gene replacement therapy for children (2+), teens, and adults living with spinal muscular atrophy (SMA) with a confirmed SMN1 mutation.

This one-time therapy targets the genetic root cause of SMA and aims to deliver freedom from chronic, ongoing treatment.

Why This Approval Matters?

For the first time, older children, teens, and adults with SMA have access to a single-dose gene therapy designed to restore functional SMN1.

What makes Itvisma different?

• One-time intrathecal dose, no weight or age adjustments.
• Directly replaces the missing SMN1 gene.
• Targets the core cause of motor neuron loss.
• Potential to reduce reliance on long-term, chronic SMA treatments.

Neurologists and patient advocates call this approval a “game-changing advance” that expands possibilities for long-overlooked segments of the SMA community.

The Evidence Behind Itvisma

The FDA decision is powered by results from two major studies:

Phase III STEER (registrational study)

• Showed statistically significant improvements in motor function.
• Demonstrated stabilization rarely seen in SMA’s natural course.
• 52-week outcomes showed sustained benefits.

Phase IIIb STRENGTH (open-label study)

• Reinforced improvements seen in STEER.
• Reported a consistent safety profile across participants.

Most common side effects

• Upper respiratory tract infection
• Fever
• Common cold
• Vomiting

The adverse events aligned with known expectations for AAV9-based therapies.

A New Era for People Living With SMA

Advocacy groups highlight what this approval really means:
Not just better scores on motor scales, but greater independence, more mobility, and a lighter treatment burden.

More than 9,000 people in the U.S. live with SMA. Many are older children, teens, and adults who still face unmet needs in preserving motor neurons and strength. Itvisma directly targets these gaps.

How SMA Works: A Quick Breakdown?

SMA is caused by mutations in the SMN1 gene, responsible for creating the SMN protein essential for muscle control. Without SMN1:

• Motor neurons degenerate
• Muscle weakness progresses
• Breathing, swallowing, and movement become impaired

The SMN2 backup gene produces only ~10% of needed SMN protein, which determines disease severity.

Itvisma replaces the missing SMN1, offering a more direct path to restoring motor neuron health.

Availability and Support

Itvisma will be available in the U.S. starting December.

Novartis is offering end-to-end patient support, including:

• Guidance on insurance
• Financial assistance options
• Personalized onboarding

Providers and patients can call 1-855-441-4363 for help.

About the Therapy: How Itvisma Works

• Delivered through a single intrathecal injection
• Uses an AAV9 vector to deliver a functional SMN1 gene
• Designed for sustained expression and long-term motor support
• Developed under multiple global licensing partnerships with leading gene therapy institutions

Novartis: Doubling Down on Neuroscience

Novartis is expanding its neuroscience pipeline across:

• Neuroimmunology
• Neurodegeneration
• Neuromuscular diseases

The goal: develop therapies that deliver meaningful, long-lasting outcomes across the lifespan.

Important Safety Insights (Short Version)

Key risks to know

• Elevated liver enzymes and hepatotoxicity
• Lower platelet counts
• Possible infections before or after treatment
• Peripheral sensory neuropathy
• Rare risk of thrombotic microangiopathy (TMA)
• Theoretical tumor formation risk with gene therapies

Patients may need:

• Corticosteroids before and after treatment
• Regular liver function tests
• Adjusted vaccination schedules
• Temporary contraception (3–6 months depending on gender)

The Bottom Line

The approval of Itvisma marks a pivotal moment for SMA care. One dose. One therapy. A chance to rewrite the future for thousands of older children, teens, and adults who previously had limited options.

This is more than another treatment milestone, it is a new chapter in genetic medicine.