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Page last checked: 9th July 2025

Zolgensma clinical trials and their results

Researchers have tested intravenous (IV) Zolgensma in human clinical trials with children up to the age of 2 years since 2014. Zolgensma 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. Trials with older heavier children are ongoing. These include giving Zolgensma via a lumber puncture (intrathecal (IT) administration).

Zolgensma 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.

Zolgensma – how it works, is given, and safety considerations – FAQs

Onasemnogene abeparvovec (Zolgensma™) uses harmless, genetically-engineered viruses to increase SMN protein levels. A single injection of Zolgensma into the blood is designed to address the genetic root cause of SMA by replacing the faulty or missing SMN1 gene.

Zolgensma – the assessment, treatment process and after care – FAQs

With the help of clinical experts, we take you through these questions.

UK Access Now – England

Infants who have SMA Type 1 and meet eligibility criteria may be assessed for NHS funded treatment with Zolgensma.

UK Access Now – Scotland

Infants who have SMA Type 1 and meet eligibility criteria may be assessed for NHS funded treatment with Zolgensma.

UK Access Now – Wales and Northern Ireland

Infants who have SMA Type 1 and meet eligibility criteria may be assessed for NHS funded treatment with Zolgensma.

Our Advocacy and Progress Towards Zolgensma Access in the UK

We have worked hard with the SMA Community, MDUK, TreatSMA and clinicians, to advocate for access. Read about this long journey.