A Hitchin dad has expressed deep concern after NHS England announced it would not fund a “wonder drug” that has changed his teenage son’s life.

Leo Martins-Hesp, a 14-year-old boy living with tuberous sclerosis and epilepsy, has had far fewer seizures and a much-improved quality of life during years on a trial for the drug everolimus.

Leo, who has a mental age of two, will still get the drug under the trial – but NHS England announced on Saturday that it would not fund it for others.

Speaking to the Comet, Leo’s dad David warned: “Somebody will probably die as a result of not being able to access this drug.”

David has found the news particularly disappointing as less than a month ago the Scottish Medicines Consortium, using the same evidence base as NHS England, recommended everolimus for NHS Scotland. The drug is also used overseas.

Tuberous sclerosis is a genetic condition that can lead to growths in various parts of the body. It is estimated to affect 10,000 people in the UK, of whom more than 80 per cent also live with epilepsy.

“For Leo and many others like him, everolimus is a wonder drug,” said David.

“Imagine watching someone you love fall to the ground or even down some stairs, shaking so violently – not being able to breathe to the point that their lips go blue. It’s so very hard to watch Leo having to go through this, always wondering if this will be the seizure that takes his life.

“The drug has also stopped the growth of bleeding tumours on his skin and other organs within his body, which presented a barrier to his being able to engage with peers of his own age.”

David has blamed the decision on a “lack of joined-up thinking between health and social care provision”, saying: “It’s quite short-sighted to look at it only from a medical perspective.”

The Tuberous Sclerosis Association, the only UK charity supporting those affected by the condition, has expressed dismay.

Charity chief executive Maxine Smeaton said: “NHS England’s decision to ignore the evidence base and feedback from experts treating and living with tuberous sclerosis is disappointing beyond words.”

She said the charity would push for NHS England to reiew this decision at its next clinical priorities advisory group meeting in November.

According to NHS England’s impact assessment, the annual cost of giving everolimus to eligible adults and children living with tuberous sclerosis in England would be just short of £60 million.

An NHS spokeswoman said: “The panel of doctors, clinicians, and the public assessed everolimus for refractory seizures associated with tuberous sclerosis complex and concluded that it delivered limited benefits compared to other treatments being considered.

“This treatment can be considered again for funding in November, but drug companies have an important part to play by pricing their treatments responsibly.”