What the trial was testing
The STEER enrolled 126 patients with spinal muscular atrophy. The study was sponsored by Novartis Pharmaceuticals and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was a large trial designed to confirm whether the treatment works well enough for wider use. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
Children receiving the gene therapy improved their motor skills by nearly 2 points more on a standard muscle function test.
Nature medicine · 2026 · NCT05089656
These findings — that children who got the gene therapy improved their ability to move nearly 2 points more than those who didn't — were published in the Nature medicine and represent the headline result of the study.
Researchers tracked outcomes across 126 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with spinal muscular atrophy, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
This one-time gene therapy is FDA-approved for spinal muscular atrophy under the brand name Zolgensma, though this specific delivery method (through the spine) may have different approval status. If your child has spinal muscular atrophy, talk to your neuromuscular specialist about whether this treatment approach is available and appropriate for your child's specific situation.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open spinal muscular atrophy trials
Vasodilator and Exercise Study for DMD (VASO-REx)
Examining two strategies as potential adjuvant therapies for Duchenne muscular dystrophy (DMD); aerobic exercise training (to induce adaptations in skeletal muscle and improve cardiovascular health) and tadalafil, an FDA-approved vasodilator (to optimize blood flow and muscle perfusion which is impaired and often overlooked in DMD). Target: improved muscle function, vascular health, and DMD treatment.
Long Term Trajectories of SMA Patients Receiving or Not Disease-modifying Treatments
This is an observational multicenter retrospective and prospective study on natural history of SMA also considering the 'new natural history' secondary to the availability of commercially available therapies. All the patients enrolled to date in the Italian registry, if not part of clinical trials, will be included in the present study.