High-Dose Spinraza Approved for Spinal Muscular Atrophy, Demonstrating Improved Motor Outcomes in Infants
Key Takeaways
- High-dose Spinraza significantly improved motor function in treatment-naïve infants vs a matched untreated cohort.
- The higher-dose regimen introduces an alternative strategy to potentially optimize treatment response in patients with SMA.
The Food and Drug Administration (FDA) has approved a higher-dose regimen of Spinraza (nusinersen; Biogen, Cambridge, MA) for the treatment of people with spinal muscular atrophy (SMA), expanding dosing options for both treatment-naïve individuals and those previously receiving standard-dose therapy.
The newly approved regimen includes an accelerated loading dose with 2 50 mg doses administered 14 days apart, followed by maintenance dosing of 28 mg every 4 months. Individuals transitioning from the standard 12 mg regimen will receive a single high-dose loading administration before continuing maintenance dosing at established intervals.
The approval was based on findings from the 3-part phase 2/3 DEVOTE study (NCT04089566), which evaluated the efficacy and safety of the higher-dose Spinraza regimen. Participants with infantile-onset SMA aged between 8 days and 7 months were included in the pivotal study population (part B), receiving the 50/28 mg high dose. The primary end point of part B was change from baseline in Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) score at 6 months.
Key Findings
- Mean change in CHOP-INTEND score was +15.1 in the high dose group vs -11.11 points in a matched untreated cohort, corresponding to a mean difference of 26.19 points (P<.0001).
- The safety profile of high-dose Spinraza was consistent with that of the standard-dose regimen.
- Common adverse events included pneumonia, COVID-19, aspiration pneumonia, and malnutrition.
Spinraza an antisense oligonucleotide targeting SMN2 splicing, has demonstrated long-term clinical benefit since its initial approval in 2016.
Source
Biogen. FDA approves new high dose regimen Spinraza (nusinersen) for spinal muscular atrophy. Biogen. Published March 30, 2026. Accessed April 3, 2026. https://investors.biogen.com/news-releases/news-release-details/fda-approves-new-high-dose-regimen-spinrazar-nusinersen-spinal