Time is motor neurons – the importance of newborn screening in SMA

Spinal muscular atrophy (SMA) is a devastating, genetic neuromuscular disease caused by a lack of a functional SMN1 gene that results in the progressive and irreversible loss of motor neurons. SMA affects approximately one in 10,000 live births worldwide.

The loss of motor neurons affects muscle functions, like breathing, swallowing, and walking. SMA, though a rare disease, is the leading genetic cause of infant death. The severity of the condition varies across a spectrum of types. In general, each corresponds to the copy number of the SMN2 gene, which produces a small fraction (~10%) of functional SMN protein, essential to the survival of motor neurons, compared with SMN1.

When left untreated in its most severe forms, SMA leads to permanent ventilation or death in 90% of cases by the age of two years.

Loss of motor neurons cannot be reversed, so patients with symptoms at the time of treatment will likely require some supportive respiratory, nutritional and/or musculoskeletal care to maximise functional abilities. This is why it is so important to detect and diagnose SMA as early as possible and begin treatment with proactive supportive care.

The main challenge in diagnosing SMA is that many clinicians do not initially recognise the early signs of the disease, which leads to delays in the diagnostic journey and, as a result, in treatment. SMA is a rare disease, therefore symptoms such as poor head control or a weak cry are often subtle at first.

“Clinical data has proven that the earlier a patient is diagnosed and treated, the better the chance of a successful outcome.”

Newborn screening has many benefits

The detection of treatable diseases through newborn screening allows for timely access to treatment and effective care, resulting in improved clinical outcomes. In SMA, for example, the earlier a baby is treated, the fewer motor neurons are lost irreversibly and the better the clinical outcome.

Caring for a child with SMA is an incredibly challenging task. Patients and their families are required to undergo regular and prolonged hospital visits, which can disrupt the child’s routine and be painful. In the early years of a patient’s life, any improvements to their quality of life will reduce the burden on their family’s lives. This will also translate for the health system overall because caring for SMA patients already costs a considerable amount of money over a patient’s lifetime.

By identifying patients with chronic diseases when they are newborns, chronic care costs per child can be reduced, which allows for cost savings and additional resources to be allocated to other areas of need. It is estimated that the cost of caring for a child with a genetic paediatric rare disease is between €2 million and €5.6 million over ten years, and these costs increase with age.

Newborn screening (NBS) is a test where a baby gets a “heel prick”, and a drop of blood is extracted and tested for known, treatable diseases. These tests help reduce the time to diagnosis and initiation of treatment.

A recent report showed that, despite NBS for different diseases existing in many EU countries, there are significant inequities within countries as to the number and types of diseases screened. For example, in Italy, screening takes place for 48 diseases, whereas in France or Spain, only six or seven diseases are included in the national NBS panels. NBS panels are updated at a country level according to local regulations, but this happens on an irregular and inconsistent basis.

Better treatments and better outcomes

Over the last decade, research has led to three different pharmaceutical treatment options for SMA, including a one-time gene therapy. Clinical data has proven that the earlier a patient is diagnosed and treated, the better the chance of a successful outcome, including the ability to achieve motor milestones that were previously unachievable for SMA babies in the natural history of the disease.

Current standard of care guidelines also recommend a proactive multidisciplinary approach following treatment. A typical treatment route for patients with SMA incorporates neuromuscular, respiratory, nutritional, orthopaedic, growth, and bone healthcare, as well as physical therapy, occupational therapy, and speech therapy. Since each avenue of therapy has different benefits to specific extremities of SMA, it is up to the child’s physician to assign an appropriate treatment route to maximise effectiveness for each individual case.

Newborn screening for SMA was added to the Recommended Uniform Screening Panel (RUSP) in the US in 2018, and now 92% of babies born in the US are screened for SMA at birth. In Europe, many countries such as Germany, Netherlands, Belgium, Czech Republic, Portugal, Norway, and Austria have added SMA to their NBS panels, as there are now effective treatments for SMA.

These countries have realised the value of being able to identify and treat these babies as early as possible. But there are still other countries, including the UK, France, Switzerland, Spain, Italy, and Greece, that have not added SMA to their national NBS panels yet. SMA Europe has launched a multidisciplinary SMA-NBS Alliance, which Novartis Gene Therapies is proud to be a part of, with the ambition to have SMA in all national NBS panels in Europe by 2025.

In summary, screening for SMA – as well as other detectable and treatable genetic diseases – is essential for realising the best possible outcomes for patients and a standard of care that lives up to the incredible new resources medicine has at its disposal.

Governments and professional organisations need to continue to work together to help ensure implementation of wider newborn screening panels with a regular and consistent framework at the national level, so that every family with a newborn baby can benefit from early diagnosis and treatment.

About the author

Mike Fraser

Mike Fraser is general manager for Europe Middle East and Africa at Novartis Gene Therapies. He has more than 20 years’ experience in the pharmaceutical industry, spanning strategy, analytics, digital innovation, early drug development, brand launches and brand management.

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