MDA 2025: Spinraza treatment stabilizes adult motor function
Study suggests long-term treatment has sustained benefits, researchers say
Treatment with Spinraza (nusinersen) can help stabilize motor function in adults with spinal muscular atrophy (SMA), according to a new analysis.
“This study aligns with previously reported findings and suggests that long-term [treatment with Spinraza] offers sustained clinical benefits in adults with SMA,” researchers wrote in the abstract for the poster, “Exploring Long-Term Outcomes of Disease – Modifying therapies on Adults with Spinal Muscular Atrophy,” which was presented at this year’s annual meeting of the Muscular Dystrophy Association (MDA).
Spinraza was the first disease-modifying therapy for SMA to win widespread approval. SMA is caused mainly by mutations in the gene SMN1, which provides instructions to make the protein SMN. A second gene called SMN2 can also make SMN protein, but produces much less protein due to a slight difference in DNA, so when SMN1 is dysfunctional the SMN2 gene cannot fully compensate. Spinraza works to boost SMN protein production by modulating the activity of the SMN2 gene.
Clinical trials have shown that Spinraza can provide sustained benefits, though studies of this therapy have focused mainly on children with SMA, and there’s less data on its effects in older patients.
Researchers at the University of Minnesota conducted an analysis on 45 people with SMA, ages 12 to 62, who were treated with Spinraza and followed for an average of 56.7 months (slightly short of five years), with a range of nine to 77 months. The work was funded by the Greg Marzolf Jr. Foundation.
Motor function stable over time
Results showed that scores on the Hammersmith Functional Motor Scale Expanded, a measure of overall motor function, did not significantly change over the course of Spinraza treatment. Scores on the Revised Upper Limb Module, a test that assesses arm and hand function, and the Modified Fatigue Impact Scale, which measures fatigue, likewise were largely unchanged over the time on Spinraza.
These trends toward stability markedly contrast with the typical progression of SMA. Without treatment, motor function and fatigue in SMA usually get progressively worse as time goes on. “Stability in motor function is likely to improve quality of life” for people with SMA, the researchers noted.
Response to treatment was consistent irrespective of the age at which patients started on Spinraza, the number of SMN2 gene copies, or each patient’s SMA type.
“These findings provide additional evidence supporting the initiation of [Spinraza] in patients across different ages and severities of SMA,” the scientists wrote in their abstract.
Spinraza is administered by injection into the spinal canal every four months. It’s sold by Biogen.
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