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Page last checked: 14th December 2022
Last updated: 23rd June 2022


This three-part study is designed to evaluate the safety, tolerability and potentially improved efficacy of nusinersen when administered at a higher dose than currently approved (12mg) for the treatment of SMA. The Phase 2/3 randomised, controlled, dose-escalating study is being conducted at approximately 50 sites around the world. It’s estimated that there are 172 participants of all ages with SMA.

The three parts consist of:

  • An open-label safety evaluation cohort (part A)
  • A pivotal, double-blind, active control randomised treatment cohort (part B) and
  • An open-label treatment cohort (part C).
    In April 2021, new data showed that:

The higher loading and maintenance dosing regimen of 28mg showed no new safety concerns in study participants who were followed for up to approximately five months (part A).

No adverse events (AEs) reported were considered related to the higher dose study drug and there were no severe or serious AEs.

This emerging safety profile supported Biogen’s continued development of a higher dose of SPINRAZA, including ongoing enrolment of patients in the pivotal Part B of the study.

Part B will evaluate the higher-dose regimen (two loading doses of 50mg two weeks apart, followed by 28mg maintenance doses every four months) compared to the approved 12mg dose of SPINRAZA: four loading doses, followed by maintenance doses every four months.


6th April: Biogen announces that they have initiated SMA patient treatment in their DEVOTE study.