FDA Approves New High Dose Regimen of SPINRAZA® (nusinersen) for Spinal Muscular Atrophy

• The approval was anchored on data from the pivotal DEVOTE study that investigated the efficacy and safety of the High Dose Regimen of SPINRAZA in treatment-naïve and previously treated SPINRAZA patients
• High Dose SPINRAZA will be available in the United States in the coming weeks and is also approved in the European Union, Switzerland and Japan

CAMBRIDGE, Mass., March 30, 2026 (GLOBE NEWSWIRE) -- Biogen Inc. (Nasdaq: BIIB) today announced that the High Dose Regimen of SPINRAZA® (nusinersen), which is comprised of 50 mg/5 mL and 28 mg/5 mL doses, was approved by the U.S. Food and Drug Administration (FDA) for the treatment of spinal muscular atrophy (SMA). Backed by more than 10 years of clinical data supporting the Low Dose Regimen of SPINRAZA (12 mg), High Dose SPINRAZA was designed to deliver a higher concentration of drug through both the loading and maintenance dosing phases, to provide a new option in response to the ongoing needs of the community.

The High Dose Regimen of SPINRAZA, which will be available in the coming weeks, enables an accelerated loading phase for those new to SPINRAZA treatment – with two 50 mg doses administered 14 days apart – followed by 28 mg maintenance dose injections every four months thereafter. Patients transitioning from the Low Dose Regimen would follow their existing dosing schedule at four-month intervals after a single High Dose loading phase.

“Optimizing the dose of nusinersen builds on a therapy that we already know can change lives. The high dose regimen demonstrated meaningful clinical benefit while maintaining a well characterized safety profile,” said Richard Finkel, M.D., director, Center for Experimental Neurotherapeutics (CENT) at St. Jude Children’s Research Hospital. “I believe High Dose Spinraza will play an important role in the future of SMA care.”

The FDA approval is based on data from the three-part, Phase 2/3 DEVOTE study. Results from the pivotal cohort of the study showed treatment-naïve, symptomatic infants who received High Dose SPINRAZA experienced statistically significant improvements in motor function as measured by the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), when compared to a prespecified matched sham (untreated) group from the ENDEAR study* (mean difference: 26.19 points; +15.1 vs. -11.1, p