Doctors have hailed a “milestone” treatment that slows or even reverses progressive muscle weakness in sufferers of motor neurone disease (MND).
New results from an international study show patients having monthly injections of the drug tofersen reported better mobility and lung function after a year of treatment.
One patient who was in a wheelchair at the start of the trial is now able to walk without sticks.
Professor Dame Pamela Shaw, Professor of Neurology at the University of Sheffield, who led the UK part of the study, said it was the first time in more than 25 trials on MND that she had seen an improvement in muscle function.
“Never before have I heard patients say: ‘I am doing things today that I couldn’t do a few months ago – walking in the house without my sticks, walking up the garden steps, writing Christmas cards,’” she said.
“For me this is an important treatment milestone.”
Motor neurone disease affects around 5,000 people in the UK. The astrophysicist Professor Stephen Hawking had the condition for many decades.
For reasons that are poorly understood, it causes the nerves that take signals from the brain to the muscles to stop working. That leads to muscle weakness and paralysis that gets worse with time and is ultimately fatal.
There are around 30 genes that are known to cause or predispose people to the disease. A mutation in one of them, called SOD1, is the trigger in about 2% of all cases.
But the new drug, made by Biogen, stops the faulty SOD1 gene from making a protein that causes nerve damage.
An earlier trial suggested six months of injections into the spinal fluid reduced levels of the SOD1 protein along with other underlying biological markers of the disease.
New updated results on 108 patients, published in the New England Journal of Medicine, show the biological effect translated into real clinical benefit after a year of continued treatment.
In those with slowly progressing MND, muscle strength actually improved slightly and disease severity remained “remarkably” stable, said Prof Shaw.
In those with more rapid progress in their disease before treatment, the decline in muscle function slowed.
Les Wood, 68, from Thorne, South Yorkshire, was diagnosed with MND 10 years ago and first took part in the trial in 2016.
He said: “After 12 months of taking the drug I could actually walk in the house without sticks, I was able to come off some of my painkillers and I felt a lot better in myself.
“It gives you hope for the future for lots of people, my own family as well, because motor neurone disease is familial in my case. Maybe my own family will benefit from this in time to come.”
Professor Chris McDermott, from the University of Sheffield Institute for Translational Neuroscience, and another of the researchers, said: “It’s having an impact and it’s a step-change for people living with this illness, but it’s not a cure.
“There are patients who don’t seem to be progressing at all, but there are others, we think with other mutations, who are progressing at a slower rate.”
Biogen is expected to submit the new results to UK, US and European drug licensing authorities. It has started an ‘early access programme’ that allows anyone with MND and the SOD1 gene to have the drug free of charge until it is available on the NHS.
The scientists are hopeful that they will be able to use the same drug design techniques to target other genes that can trigger MND, leading to an era of personalised medicine.
“These principles that have emerged from this trial are a real source of hope for MND patients as a whole,” said Prof Shaw.
“If you are a patient or a family facing a disease like MND the pace of science and medicine does seem painfully slow.
“But this indicates we are in a new era where we can expect real progress – not a miraculous cure overnight, but where there is slowing disease progression.
“It will make the disease much more liveable and much less scary.”