Zolgensma benefits observed in presymptomatic SMA patients

Early treatment with Onasemnogen Abeparvovec-xioi (Zolgensma®; Novartis) led to age-appropriate development in patients with spinal muscular atrophy. This is evident from research presented at the Muscular Dystrophy Association (MDA) virtual clinical and scientific conference in 2021.

The Phase 3 SPR1NT study ( NCT03505099) is an ongoing, open-label, single-arm study to evaluate the efficacy and safety of Onasemnogen Abeparvovec in presymptomatic patients (6 weeks and younger) with a genetic diagnosis of SMA and 2 or 3 Copies of the survival motor neuron 2 gene (SMN2).

Results showed that as of June 11, 2020, 79% of patients (n = 11/14) with a mean age of 15.6 months in the 2-copy cohort met the primary endpoint of unassisted sitting for at least 30 seconds; 10 patients reached this mark in the World Health Organization (WHO) window of normal development. In addition, 36% of the patients (n = 5/14) could stand independently and 29% (n = 4/14) could walk independently. Among the patients who had not reached these milestones, the researchers reported that the majority had not yet passed the normal development window.

In addition, all patients achieved a CHOP INTEND (Child Hospital of Philadelphia Infant Test of Neuromuscular Disorders) score of at least 50, with 93% of patients (n = 13/14) achieving a CHOP INTEND score of at least 58 in all patients a raw score of the fine and gross motor Bayley III scales were observed.

In the 3-copy cohort, 53% of patients (n = 8/15) with a mean age of 15.2 months achieved the primary endpoint of standing alone for at least 3 seconds, while 40% (n = 6/15) could go independently. It was reported that patients who had not yet reached these milestones were still within the WHO window of normal development. A steady increase in the mean raw score of the fine and gross motor Bayley III scales was observed in all of these patients.

“When treated with Zolgensma prior to the onset of symptoms, children in the SPR1NT study achieved milestones such as sitting, standing, and walking at an appropriate age, grew as expected without nutritional assistance, and were devoid of any form of mechanical ventilation assistance,” said Kevin Strauss , MD, Medical Director, Pennsylvania Clinic for Special Children. “The transformative benefits of early intervention as seen in SPR1NT further underscore the urgent need for neonatal screening.”

Zolgensma is currently approved for the treatment of pediatric patients under 2 years of age with SMA with bi-allelic mutations in the SMN1 gene. The gene therapy based on recombinant adeno-associated viruses is intended to provide a copy of the gene that codes for the human SMN protein.


New Zolgensma data show age-appropriate development when used early, real benefit in older children, and shelf life of more than 5 years after treatment. [press release]. Basel, Switzerland: Novartis; March 15, 2021.

This article originally appeared on MPR

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