FDA Approves Higher-Dose Spinraza for Spinal Muscular Atrophy

On March 30, 2026, the U.S. Food and Drug Administration (FDA) approved a higher-dose regimen of Biogen's spinal muscular atrophy (SMA) drug, Spinraza (nusinersen). This decision comes after the FDA previously rejected the application in 2025, seeking revisions to the chemistry manufacturing and controls module. The new treatment protocol includes two initial doses of 50 milligrams administered 14 days apart, followed by a maintenance dose of 28 milligrams every four months. This contrasts with the previous standard dose of 12 milligrams.

US Stocks: Biogen gets FDA approval for higher dose of genetic disorder drug, shares rise 3%ReutersBiogen receives FDA nod for high-dose regimen of SPINRAZA

The approval is significant for Biogen, which faces increasing competition from other therapies, including Roche's oral drug Evrysdi and Novartis' gene therapies Zolgensma and Itvisma. Following the announcement, Biogen's shares rose approximately 3.3%. The new regimen is expected to address the waning treatment effects experienced by some patients, potentially allowing Biogen to penetrate a broader adult population and drive growth from 2026 onwards. Jefferies analyst Andrew Tsai noted that the higher-dose Spinraza could enhance treatment efficacy and market reach.

US Stocks: Biogen gets FDA approval for higher dose of genetic disorder drug, shares rise 3%ReutersBiogen receives FDA nod for high-dose regimen of SPINRAZA

The FDA's approval was supported by data from the Phase 2/3 DEVOTE study, which demonstrated a mean improvement of 26.19 points on the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) score in infants receiving the higher-dose regimen compared to a matched sham control group. The safety profile of the higher-dose version was found to be similar to that of the lower-dose regimen, reinforcing its viability as a treatment option.

Biogen receives FDA nod for high-dose regimen of SPINRAZAUS Stocks: Biogen gets FDA approval for higher dose of genetic disorder drug, shares rise 3%Reuters

Biogen plans to introduce the 28 mg vial at a list price of approximately $152,000, the same as the 12 mg vial, while the 50 mg vial will be priced around $271,000. The higher-dose Spinraza will be available to patients in the United States in the coming weeks and has also received approval in the European Union, Switzerland, and Japan.

Reuters

Despite the approval, some analysts and stakeholders express concerns regarding the pricing strategy and the long-term efficacy of Spinraza compared to emerging therapies. Critics argue that the high cost may limit accessibility for patients who need the treatment.

Reuters

• “Higher-dose Spinraza could address the waning-off effect experienced by patients with a more rapid loading dose, which could better position Biogen to penetrate the broader adult population and potentially drive growth from 2026 onwards, said Jefferies analyst Andrew Tsai.” — Andrew Tsai, Jefferies Analyst

US Stocks: Biogen gets FDA approval for higher dose of genetic disorder drug, shares rise 3%

• “Biogen's application was backed by mid-to-late-stage trial data that showed the higher-dose version significantly improved motor function in infants compared to untreated patients, with a safety profile similar to the low-dose regimen.” — Biogen Statement

US Stocks: Biogen gets FDA approval for higher dose of genetic disorder drug, shares rise 3%

The approval of the higher-dose Spinraza represents a pivotal moment for Biogen as it seeks to maintain its position in the competitive SMA treatment landscape while addressing the needs of patients.

Reuters