Evrysdi

Pharmaceutical company: Roche

Our genes act as the instructions to make proteins, which play a vital role in all the tasks our cells do. People with SMA lack some of the instructions (SM1 gene) needed to make a protein called ‘survival motor neuron’ (SMN). This protein is essential for the health and survival of nerve cells which help to control muscles.

There are ‘back up’ instructions (SM2 gene), which produces a smaller amount of working SMN protein. Evrysdi modifies how the ‘back up’ instructions are used to make the SMN protein, leading to increased levels of working SMN protein.

Evrysdi comes as a solution that can be swallowed. Roche have also developed a tablet form of Evrysdi which can be swallowed or dissolved in water.

Spinraza has been recommended as a treatment option for people with spinal muscular atrophy in the UK. Please contact your (or child’s) clinical team for more information.

England, Wales and Northern Ireland

Read the full National Institute for Health and Care Excellence (NICE) guidance.

Scotland

Read the full Scottish Medicines Consortium (SMC) guidance.

For over ten years the SMA community has tirelessly campaigned for access – we are proud to have worked alongside the community to ensure access. This involved working in partnership with charities SMA UK and Treat SMA, to ensure the experience and views of the SMA community were heard.

Evrysdi has been tested in many clinical trials, in people with type 1,2 and 3 SMA, as well as newborns who are pre-symptomatic. Pre-symptomatic means babies have a genetic change associated with SMA but are not yet showing symptoms. All the trials found Evrysdi to be safe.

Type 2 or 3 SMA

In the phase 3 SUNFISH trial, 231 participants with type 2 or 3 SMA, aged between 2 and 25 years were randomly assigned to receive Evrysdi (115 participants) or placebo (dummy drug, 59 participants). After 12 months, participants who received Evrysdi had improvements in motor function (ability to move, as measured by a series of tests called the MFM-32 score), compared to those who received the placebo. However, this was not statistically significant, meaning the researchers couldn’t confirm the results weren’t due to chance.

Type 1 SMA

In the FIREFISH trial, all 62 infants with type 1 SMA, aged between one and seven months old were given Evrysdi. There was no placebo, instead the researchers compared against natural history data. This is where infants with SMA are followed to gather information on the natural progression and impact of the condition. They have not received the treatment.

• After 12 months, almost a third (29%) of infants who received Evrysdi were siting without support for at least 5 seconds.
• Natural history data suggests that, without treatment, 5% of the infants would be expected to sit without support for at least 5 seconds.
• After 24 months, 61% of the infants who received Evrysdi could sit without support for at least 5 seconds, however this was not compared to any data from infants who didn’t receive the treatment.

Pre-symptomatic SMA

In the RAINBOWFISH trial, all 26 newborns with pre-symptomatic SMA (have a genetic change associated with SMA but are not yet showing symptoms) aged 16 – 41 days old, were given Evrysdi. There was no placebo, instead the researchers compared against natural history data.

• After 12 months, many (81%) of the infants who received Evrysdi were able to sit without support for at least 30 seconds.
• Natural history data suggests that, without treatment, infants with type 1 SMA would never be able to sit without support.

It is important to note that natural history data can come with some limitations. Placebo controlled clinical trials are the gold standard in gathering evidence to determine if a treatment has a beneficial effect, as they can make the evidence collected more reliable. However, researchers also consider how ethical it is to use a placebo when designing trials. It can also be difficult to find enough participants to carry out placebo controlled clinical trials for rare diseases.

Last updated: 15/05/2026