A five-month-old baby has become the first patient in England treated with Zolgensma, a potentially life-saving drug, on the NHS that can prolong the lives of children with spinal muscular atrophy.

Arthur Morgan, diagnosed with the condition earlier this month, received the one-off gene therapy at Evelina London Children’s Hospital on May 25.

Zolgensma, which has a list price of £1.795 million per dose, was made available on the NHS after the health service struck a deal with manufacturers Novartis Gene Therapies in March.

There were no treatment options available for children with spinal muscular atrophy until two years. Babies born with type 1 SMA – the most common form of the condition – experience progressive muscle weakness, loss of movement, difficulty breathing,

In studies, a single treatment with Zolgensma has helped babies with SMA to sit, crawl and walk and also prevented them from having to be put on a ventilator.