Biogen Receives European Commission Approval For High-Dose SPINRAZA To Treat 5q Spinal Muscular Atrophy, Offering Faster Loading And Extended Maintenance Doses

Biogen Inc. announced that the European Commission has granted marketing authorization for a high-dose regimen of SPINRAZA® (nusinersen) for the treatment of 5q spinal muscular atrophy (SMA). The updated regimen includes 50 mg and 28 mg doses and is designed to provide a more rapid loading phase for patients. SMA is the most common form of the disease, accounting for approximately 95% of cases. 

The high-dose regimen involves two 50 mg loading doses administered 14 days apart, followed by 28 mg maintenance doses every four months. Patients transitioning from the previous 12 mg regimen will receive a single 50 mg dose in place of their next 12 mg dose, followed by 28 mg maintenance doses. SPINRAZA is administered intrathecally via lumbar puncture by healthcare professionals trained in the procedure.

Priya Singhal, M.D., M.P.H., Executive Vice President and Head of Development at Biogen, highlighted that since its initial approval in the European Union in 2017, SPINRAZA has treated more than 10,000 patients across all age groups. She emphasized that the high-dose regimen was developed to address evolving needs in the SMA community and expressed Biogen’s commitment to making this treatment available as quickly as possible. She also acknowledged the contributions of the SMA community in achieving this milestone.

The European Commission’s approval is based on data from the three-part, Phase 2/3 DEVOTE study and its ongoing long-term extension. Results from the pivotal cohort showed that treatment-naïve symptomatic infants receiving the high-dose regimen experienced statistically significant improvements in motor function, as measured by the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), compared with a matched sham group from the ENDEAR study (mean difference: 26.19 points; +15.1 vs. -11.1, p<0.0001). Improvements were also observed in older patients and those transitioning from the low-dose regimen, with participants achieving a mean improvement of 1.8 points on the Hammersmith Functional Motor Scale – Expanded from baseline to Day 302.

Eugenio Mercuri, M.D., Ph.D., Professor of Pediatric Neurology at the Catholic University in Rome, noted that the DEVOTE study provides encouraging evidence that the high-dose regimen may deliver meaningful treatment outcomes while maintaining a safety profile similar to the previous 12 mg dosing. He added that this approval represents an important step toward improving care for people living with SMA.

The high-dose regimen was generally well tolerated during the study, with adverse events consistent with the underlying disease and the known safety profile of nusinersen. No new safety concerns were identified during long-term follow-up. Common adverse events observed in at least 10% of participants and occurring more frequently than in the matched sham group included pneumonia, COVID-19, aspiration pneumonia, and malnutrition. Special precautions for use include risks associated with the lumbar puncture procedure, low platelet counts, blood clotting abnormalities, renal toxicity, and hydrocephalus.

Nicole Gusset, CEO of SMA Europe, welcomed the approval, highlighting that expanding treatment options supports continued innovation and the development of more personalized approaches to SMA care. The updated Summary of Product Characteristics for SPINRAZA will be available on the European Medicines Agency website. The high-dose regimen is also approved in Japan and is under review by the U.S. Food and Drug Administration, with a decision expected by April 3, 2026. Biogen is actively engaging with regulatory authorities globally to make this additional dosing option available to patients living with SMA.