FDA Approves Biogen’s High-Dose SPINRAZA To Enhance Treatment Outcomes In Spinal Muscular Atrophy

Biogen Inc. announced that the U.S. Food and Drug Administration has approved a high-dose regimen of SPINRAZA® (nusinersen) for the treatment of spinal muscular atrophy (SMA). This new dosing approach builds on more than a decade of clinical experience with the existing low-dose regimen and is designed to deliver higher drug concentrations to better address patient needs.

“Nearly ten years ago, the approval of SPINRAZA marked a turning point in SMA care and changed what the community believed was possible, with Biogen becoming a trusted partner for thousands of people living with SMA. Today’s approval of High Dose SPINRAZA makes progress in addressing unmet needs of the SMA community,” said Kenneth Hobby, President of Cure SMA. “Biogen understands the needs of the SMA community and has remained a committed and engaged partner to advance research that can improve the daily lives of people living with SMA.”  

The high-dose regimen includes an accelerated loading phase for new patients, consisting of two 50 mg doses administered two weeks apart, followed by maintenance doses of 28 mg every four months. Patients already receiving the low-dose version can transition to the new regimen with a single high-dose loading phase while maintaining their regular dosing schedule.

“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.”

Approval was based on findings from the Phase 2/3 DEVOTE study, where symptomatic infants treated with high-dose SPINRAZA showed significant improvements in motor function compared to untreated controls from the ENDEAR study. The results demonstrated a notable increase in CHOP-INTEND scores, highlighting meaningful clinical benefits for patients with SMA.

“Over the past decade, Biogen has continued to listen, learn, and innovate to help advance care for people living with SMA,” said Priya Singhal, M.D., M.P.H., Executive Vice President and Head of Development at Biogen. “With more than 10 years of clinical data on SPINRAZA, the development of the High Dose Regimen reflects both the strength of that foundation and our unwavering commitment to the SMA community to optimize treatment options. We are grateful to the community for their support and contributions toward this milestone.”

The safety profile of the high-dose regimen was consistent with the established profile of the lower dose, with commonly reported adverse events including pneumonia, COVID-19, aspiration pneumonia, and malnutrition in infant patients. The high-dose option has also been approved in other regions, including Europe, Switzerland, and Japan, with global regulatory efforts ongoing to expand access.