NEW YORK – Novartis said on Monday it plans to share topline data from the Phase III trial of its gene therapy Zolgensma (onasemnogene abeparvovec) with regulatory agencies in 2025, including the US Food and Drug Administration, after seeing positive results in pediatric and young adult patients with spinal muscular atrophy (SMA).
The Phase III STEER study met its primary endpoint of an increase in Hammersmith Functional Motor Scale - Expanded (HFMSE) scores from baseline, an indicator of improved motor function for SMA. Patients treated with Zolgensma in the study experienced an increase in their HFMSE scores, indicating better motor function after receiving the therapy.
The trial included patients between ages 2 and 18 with SMA who are able to sit but have never walked independently. Researchers compared the gene therapy Zolgensma against a sham control, which mimicked the administration of an investigational drug without delivering any active treatment.
Novartis also reported that the safety profile of Zolgensma was favorable, and that the adverse events and serious adverse events were similar between study arms. The full results will be presented at a medical meeting in 2025.
Zolgensma is currently approved in the US for the treatment of patients less than 2 years of age with SMA with biallelic mutations in the survival motor neuron 1 (SMN1) gene. The one-time therapy uses an Adeno-associated virus (AAV9) to deliver a working copy of the SMN1 gene that allows cells to produce functional SMN protein.
"Maintaining motor function is a key goal for many older patients with SMA," Crystal Proud, pediatric neurologist and a principal investigator at Children's Hospital of the King's Daughters, said in a statement. "This may allow them the capacity to continue to propel their electric wheelchair, feed themselves with intact hand-to-mouth function, and perform other activities of daily living as independently as possible. OAV101 IT administration has not only been demonstrated to maintain motor function, but also increased it in indicating the impact a one-time therapy could have."