A drug capable of significantly delaying the progression of motor neurone disease (MND) will not be available on the NHS because not enough people can benefit from it.

Studies show that tofersen is very effective in combating this deadly muscle-wasting disease, but only in patients with a specific genetic mutation, called SOD1.

This means only around 100 of the 5,000 MND patients in the UK could benefit. Experts predict that, for these patients, the £100,000-a-year treatment could stall their disease for several years or even decades. However, Biogen, its US developer, has decided not to seek approval for tofersen in the UK because it believes the NHS spending watchdog would reject it given the small patient group.

Campaigners are now calling on the watchdog, the National Institute for Health and Care Excellence (NICE), to commit to approving the treatment.

Tim Wake, 45, was diagnosed with MND in 2020 and benefited from the drug Tofersen

MND causes muscles to weaken and, in severe cases, to stop functioning completely. The first signs are often slurred speech and muscle cramps. For those most affected, the lungs and throat eventually stop working, leading to death.

Tim Wake, 45, from Surrey, who was diagnosed with Tofersen in 2020, is one of the MND patients who has benefited from Tofersen. His mother, grandmother and uncle all died from the disease.

“I had hoped that my side of the family would not have been affected, but when I heard the news it was devastating,” says the operations manager.

“My symptoms appeared very quickly. In July I was very active, running and playing soccer with the kids, until I found myself in a wheelchair in October.

Having been identified as a carrier of the SOD1 gene, Mr Wake was offered the opportunity to take part in a clinical trial in which he received monthly spinal injections of tofersen. The drug had an instant effect on him.

Former rugby league star and campaigner Rob Burrow died earlier this year aged 41 due to MND.

“I haven’t progressed in four years, which is astounding,” he said. “Without it, I would almost certainly have died, judging by what happened to my mother. I’ve seen the kids grow up, supported my career, and lived a pretty normal life.

Earlier this year, former rugby league star and campaigner Rob Burrow died aged 41 from MND. He was diagnosed in December 2019 and it quickly left him unable to move.

Until now, there was no drug treatment that could slow MND. However, in 2022, a major study of tofersen found that, for 2% of MND patients, it was life-changing.

The research, published in the New England Journal, involved 108 patients from 32 sites across ten countries, all carrying the SOD1 gene mutation.

When the gene is mutated, the body produces toxic proteins that damage muscles. The innovative drug – known as a gene silencer – effectively inhibits the faulty gene, thereby reducing SOD1 protein production.

Researchers found that monthly spinal injections allowed patients to report significantly better mobility and lung function after 12 months.

Burrow lived with the disease for five years, after being diagnosed in late 2019

“We’ve never had anything like this. It’s truly remarkable,” said Professor Ammar Al-Chalabi, a neurologist at King’s College London. “Trials show that when given to patients at an early stage, it stops progression and, in some cases, even improves their condition.”

But despite approval from EU health officials earlier this year, there are no plans to make it available on the NHS.

Pharmaceutical giant Biogen said it did not think it would be approved if submitted to NICE, saying the watchdog would assess tofersen only as a treatment for MND overall.

Since it only benefits 2% of total MND patients, Biogen says it is unlikely to be considered a profitable drug – the crucial barometer for a drug to secure NHS funding .

The disagreement also means that UK patients currently receiving tofersen injections as part of the trial will no longer be able to access them, again putting their lives at risk.

NICE has been contacted for comment.