The NHS have granted approval for the use of the world’s most expensive drug, Zolgensma, on a 10-month-old child with severe spinal muscular atrophy (SMA). If successful, the drug could prolong baby Edward’s life expectancy from just two years to significantly longer, and allow him independence never before seen for patients with the lifelong disease.
The news comes after a long and arduous campaign by Edward’s mother, Megan Willis, to allow her child to be treated with the new gene therapy. However, sitting at an astonishing $2.48 million (£1.79 million) for just one treatment, it has been a struggle to gain approval on the NHS. In diseases such as SMA, time is a key predictor of prognosis – get treatment early in disease progression, and the outcome is far better, so each day counts.
“I’m exhausted. It’s been such a long ride and a rollercoaster,” said Megan, speaking to the Guardian.
“When I think back to myself in November, newly diagnosed, I didn’t think there was an option for him – I thought he was dying because that’s that all it said when I read up on SMA, that 95% of children die, or are severely disabled. I didn’t think he had a future.”
Spinal muscular atrophy is a genetic disorder that varies in severity, but at its most severe it causes muscle weakness, movement problems, difficulty breathing, and eventual death. The symptoms get worse with age, and affected children often pass due to respiratory failure as young as two years old. Most commonly inherited from the parents, SMA is thought to be caused by mutations within the SMN1 gene, which codes for the survival motor neuron protein (SMN), a protein that is vital for maintenance of motor neurons. As the gene is mutated, SMN production is decreased and motor neurons begin to die, preventing signals from passing from the brain to the muscles.
In an attempt to combat the missing SMN, Zolgensma introduces a healthy copy of SMN1 using virus vectors into nerve cells. Once incorporated, this gene allows the cells to produce SMN once more, allowing the affected person to maintain nerve cells and halt disease progression.
Zolgensma was approved for use by the FDA in May 2019, and by NICE for use in the UK in March 2021. As SMA is a degenerative disorder, long-term data on the efficacy of Zolgensma is lacking, but early results suggest the single-dose therapy is able to vastly improve motor function in young children with type 1 SMA. Current therapies involve regular injections every four months for the lifetime of the patient, but Zolgensma claims to produce similar quality of life improvements from just a single treatment.
It is currently only approved for babies less than six months old, but cases are dealt with individually to allow use for older children such as Edward.