Skip to content
Page last checked: 9th July 2025

Nusinersen clinical trials and their results

Researchers have tested nusinersen in human clinical trials since 2011. Nusinersen is not a cure for 5q SMA but in these trials, it has been consistently shown to have an acceptable safety profile and to be well-tolerated. When compared to no treatment, it has led to clinically meaningful improvements in muscle function. Several trials of nusinersen are still ongoing.

Nusinersen works best if started before there is any muscle weakness, or when this is minimal. It is therefore important for treatment to be started as soon as possible.

What is it, how does it work, how is it given – FAQs

Nuisnersen (Spinraza™) is an antisense oligonucleotide. It is designed to modify the product of the SMN2 “backup” gene to produce more functional SMN protein.

UK access now – England

Nusinersen is funded by the NHS via a Managed Access Agreement.

UK access now – Scotland

Nusinersen is funded by the NHS and is available for children. Though there is provision in the NHS agreement for adults, there is no treatment centre in Scotland delivering nusinersen.

UK access now – Wales and Northern Ireland

Wales and NI follow NICE guidance for England and the guidelines of the Managed Access Agreement.

Other published summaries of treatment outcomes

Our advocacy and progress towards access to Nusinersen in the UK

We have worked hard with the SMA Community, Muscular Dystrophy UK, TreatSMA and clinicians to advocate for access, and will continue to work towards access throughout the UK.