Babies with rare muscle-wasting disease living longer thanks to treatment advances

NHS started rolling out treatments for spinal muscular atrophy in 2019

Almost three-quarters of babies born with a rare muscle-wasting disease are living longer thanks to advances in NHS treatment.

Spinal muscular atrophy (SMA) is a genetic condition that causes muscle weakness, along with progressive loss of movement and paralysis.

There are three types of this disease that impact children.

SMA1 manifests in babies under the age of six months and is the most severe, while SMA2 and SMA3 are less severe. They develop between the ages of seven and 18 months, and after 18 months of age, respectively.

According to the NHS, about 70 babies are born in the UK with SMA each year.

The NHS began rolling out new treatments in 2019, starting with injectable drug nurinersen – marketed as Spinraza – which targets the SMN2 gene in patients.

Before 2019 there were no effective drugs for this condition... we’re delighted that access to these new and transformative treatments through the NHS is already making a real difference for families

Amanda Pritchard, NHS England chief executive

This was followed by gene therapy zolgensma and oral treatment risdiplam in 2021.

NHS England chief executive Amanda Pritchard said: “It’s fantastic to see that more and more children diagnosed with this debilitating condition are living longer and with greater independence, thanks to cutting-edge treatments now available on the NHS.”

A study by SMA Reach UK claims patients with untreated SMA1 historically had a 50% survival probability at eight to 10 months, reducing to 8% at 20 months of age.

However, data from the SMA Reach UK database analysed by NHS England found 73% of babies with SMA1 are now living beyond two years and without permanent ventilatory support.

Ms Pritchard added: “Before 2019 there were no effective drugs for this condition, and while there is so much still to do, we’re delighted that access to these new and transformative treatments through the NHS is already making a real difference for families, enabling more babies to stand up and take steps.

“This is yet another example of the NHS leading the way in securing access to innovative treatments for those with rare genetic conditions while delivering value for the taxpayer – and with the expertise of our phenomenal paediatricians and wider specialists, we hope that outcomes for children born with SMA will continue to improve in the coming years.”

The SMA Reach UK study also suggests there has been a reduction in deaths from SMA1 in recent years.

According to the Office for National Statistics, there were 11 deaths from the condition recorded between March 2018 and March 2023 compared to about 25 per year in England between 2008 and 2017.

Giles Lomax, chief executive of charity Spinal Muscular Atrophy UK (SMA UK), said the treatments have had “transformative effects” but early access to them is crucial.

“Early access to these treatments is imperative to prevent irreversible muscle degeneration and that’s why SMA UK are advocating for SMA to be included on the newborn screening programme.

“One baby every five days is born with SMA and the sooner they receive treatment the sooner their condition will stabilise.

“It’s vitally important that the NHS continue to prioritise these lifesaving services to ensure that everyone with SMA can live the best independent life possible.”