The Food and Drug Administration (FDA) has approved Zolgensma (onasemnogene abeparvovec-xioi; Novartis) for the treatment of children less than 2 years of age with spinal muscular atrophy (SMA) with bi-allelic mutations in the survival motor neuron 1 (SMN1) gene.
Zolgensma is a recombinant adeno-associated virus vector-based gene therapy designed to deliver a copy of the gene encoding the human SMN protein. The approval was based on data from the ongoing phase 3 STR1VE trial and the completed phase 1 START trial. In both studies, patients were administered a single-dose intravenous infusion of Zolgensma.
“In the START clinical trial we conducted with Zolgensma, all children were alive at the conclusion of the study and many were able to sit, roll, crawl, play and some could walk,” said Jerry Mendell, MD, principal investigator at the Center for Gene Therapy at The Abigail Wexner Research Institute of Nationwide Children’s Hospital in Columbus, OH. “This level of efficacy, delivered as a single, one-time therapy, is truly remarkable and provides a level of unprecedented hope for families battling SMA Type 1. We now have data 4 years out from the trial, and we see the durability of this gene therapy.”
The ongoing STR1VE trial is an open-label, single-arm study (N=21) that currently includes 19 patients ranging in age from 9.4 to 18.5 months. The primary endpoints are based on achievement of independent sitting for at least 30 seconds (18 months of age visit) and event-free survival (defined as avoidance of death or permanent ventilation); secondary endpoints include the ability to thrive and ventilatory support independence through 18 months of age.
By data cutoff, results showed 13 of the 19 patients reached 14 months of age without permanent ventilation; 10 of the 21 patients (47.6%) achieved the ability to sit without support for ≥30 seconds between 9.2 and 16.9 months of age (mean age was 12.1 months); 16 of the 19 patients had not required daily non-invasive ventilator (NIV) use.
Zolgensma carries a Boxed Warning regarding the risk of serious liver injury. Liver function should be assessed prior to infusion. The most common adverse reactions associated with therapy included elevated aminotransferases and vomiting.
Zolgensma is available as a suspension for intravenous infusion in single-use vials. A treatment guide for healthcare providers can be found here.
For more information visit zolgensma.com.