FDA approves Biogen’s high-dose Spinraza regimen for spinal muscular atrophy, supported by DEVOTE trial data showing significant motor function gains.
Written By: Karthik Teja Macharla, PharmD
Reviewed By: Pharmacally Editorial Team
Biogen Inc. has received approval from the U.S. Food and Drug Administration for a new high-dose regimen of Spinraza (nusinersen) for the treatment of spinal muscular atrophy (SMA),
The newly approved regimen includes 50 mg/5 mL and 28 mg/5 mL doses, designed to increase drug exposure during both loading and maintenance phases. Built on more than a decade of clinical experience with the 12 mg regimen, the updated dosing strategy aims to further optimize treatment outcomes for patients.
The regimen introduces an accelerated loading phase for treatment-naïve patients, consisting of two 50 mg doses administered 14 days apart, followed by 28 mg maintenance doses every four months. Patients transitioning from the low-dose regimen can receive a single high-dose loading phase and continue maintenance dosing at the same interval.
Approval is supported by data from the Phase 2/3 DEVOTE study (NCT04089566). In the pivotal cohort, treatment-naïve symptomatic infants receiving high-dose Spinraza showed statistically significant improvements in motor function versus a matched untreated group from the ENDEAR study. Using the CHOP-INTEND scale, the mean difference reached 26.19 points (+15.1 vs. −11.1; p<0.0001), indicating substantial clinical benefit.
The safety profile observed in DEVOTE remained consistent with the established experience of Spinraza. The most common adverse events reported more frequently than in historical controls included pneumonia, COVID-19, aspiration pneumonia, and malnutrition, particularly among infants with early-onset SMA.
Richard Finkel M.D., director, Center for Experimental Neurotherapeutics (CENT) at St. Jude Children’s Research Hospital highlighted that increasing nusinersen dosing builds on a therapy already proven to transform patient outcomes, with the high-dose regimen delivering added clinical benefit while maintaining a well-understood safety profile, reinforcing its expected role in future SMA care.
Priya Singhal M.D., M.P.H., Executive Vice President and Head of Development at Biogen emphasized that the development reflects Biogen’s decade-long commitment to the SMA community, leveraging extensive clinical experience with Spinraza to refine and expand treatment options.
Kenneth Hobby President of Cure SMA, noted that Spinraza’s original approval reshaped expectations in SMA, and the high-dose option represents continued progress toward addressing remaining unmet needs while strengthening Biogen’s long-standing partnership with the patient community.
High-dose Spinraza has also been approved in the European Union, Switzerland, and Japan, with further global regulatory discussions ongoing.
For detailed prescribing information, including safety, warnings, and precautions, refer to the official US prescribing information here
References
FDA Approves New High Dose Regimen of SPINRAZA® (nusinersen) for Spinal Muscular Atrophy, 30 March 2026, FDA Approves New High Dose Regimen of SPINRAZA® (nusinersen) for Spinal Muscular Atrophy | Biogen
Study of Nusinersen (BIIB058) in Participants with Spinal Muscular Atrophy (DEVOTE), ClinicalTrials.gov ID NCT04089566, https://clinicaltrials.gov/study/NCT04089566