For SMA Patients, Zolgensma Outperforms Other Gene Therapies, Review Shows

A comprehensive analysis of treatments for spinal muscular atrophy (SMA) found Zolgensma (onasemnogene abeparvovec) is more effective compared with other similar available therapies. Zolgensma, which was developed by Novartis, is a one-time gene therapy

The systematic review and meta-analysis, published last week in Gene Therapy, evaluated 57 studies involving more than 3,400 SMA patients, compared outcomes between different treatment options. The research team, led by Bunchai Chongmelaxme of Chulalongkorn University, found Zolgensma achieved a 95% survival rate, outperforming both Evrysdi (risdiplam) at 86% and Spinraza (nusinersen) at 60%.

“Although the benefits of gene-based therapy for SMA have been demonstrated in various studies, healthcare professionals and policymakers still face numerous challenges in identifying the most effective treatment for individuals,” the study authors wrote. “This study aimed to determine the effects of gene-based therapy on patient survival, the need for ventilatory support, motor function improvement, and the incidence of adverse drug reactions.”

Related: Older Ventilated Children with SMA See Improvements After Gene Therapy

Key findings included that Zolgensma was the only treatment to reduce the number of patients requiring ventilatory support. The therapy also demonstrated the highest rate of motor function improvement, with 92% of patients showing better scores on standardized testing. Evrysdi showed similar motor improvement rates at 90%, while Spinraza helped 74% of patients achieve better scores.

The analysis found similar safety profiles across treatments, with headaches, vomiting and gastrointestinal issues being the most commonly reported side effects.

Left untreated, the rare genetic neurodegenerative disorder is typically fatal for children by age two. However, the FDA approval of disease-modifying therapies including Spinraza in 2016, Zolgensma in 2019 and Evrysdi in 2020 have transformed the treatment landscape. Now, with early screening and presymptomatic treatment shortly after birth, babies with SMA can achieve normal motor milestones.

The study did have some limitations: the researchers noted the studies included in their analysis collected varying patient characteristics and had different observation periods, making direct comparisons challenging.

“Gene-based therapy benefits patient survival and improves motor function,” the study authors wrote. “[Zolgensma] and [Evrysdi] appear highly effective, whereas [Spinraza] exhibits moderate effectiveness.”