Scientists and doctors in the US and Europe have for the first time managed to slow down the development of the incurable Huntington's disease by four times—and by using gene therapy.

The company uniQure, which had organized the trials of the new method, announced that in several dozen volunteer patients from the US and Europe, who were operated on in 2022 and then were under study for three years, the rate of development of Huntington's disease slowed down by 75%.

The first symptoms of Huntington's disease usually appear after the age of 30, and the patient dies no later than 20 years later.

“It means the decline you would normally expect in one year would take four years after treatment, giving patients decades of ‘good quality life,’" Sarah Tabrizi, professor of clinical neurology and Director of the Huntington's Disease Centre at University College London—and who took part in the trial, told BBC News.

"We never in our wildest dreams would have expected a 75% slowing of clinical progression," she said.

“There was every chance that we would never see a result like this, so to be living in a world where we know this is not only possible, but the actual magnitude of the effect is breathtaking, it's very difficult to fully encapsulate the emotion.,” says Professor Ed Wild, consultant neurologist at the National Hospital for Neurology and Neurosurgery at UCLH.

Treatment is likely to be very expensive.

Huntington’s disease is a genetic, inherited disease that destroys brain cells and has symptoms similar to dementia, Parkinson’s disease, and motor neuron disease, which causes paralysis. It is caused by a mutation in the protein huntingtin, which destroys brain cells. If one parent has this mutation and develops Huntington’s disease, the child has a 50% risk of developing the disease.

The uniQure team has developed a breakthrough method that, based on these preliminary results, enables for a single, complex surgery using advanced genetic medicine techniques to reduce the level of huntingtin in the body.

First, doctors genetically modify a harmless virus so that it contains a specific DNA sequence.

Then, during an operation lasting up to 18 hours, it is introduced into certain parts of the brain using microcatheters and MRI.

There, the virus begins to work as a “micro postman,” delivering a specially constructed DNA fragment to brain cells, neurons, and they begin to independently produce an antidote against mutated huntingtin.

The names of the 29 patients who received a full dose of the modified virus—there were also control groups—are not disclosed, but the participants in the experiment said that one of them was discharged and went to work, and the others, instead of moving around in a wheelchair, walk without help.

Until now, all that medicine could offer to those suffering from Huntington’s disease was palliative care in the final stages.

Huntington's disease affects about 75,000 people in the US and Europe, and hundreds of thousands more are carriers of the mutated protein, which means they are potentially susceptible.

The new method, which is complex and expensive, will not be available to everyone at first.

"It will be expensive for sure," admits Professor Ed Wild.

There isn't an official price for the drug yet. uniQure, which is headquartered in the US and the Netherlands, first intends to obtain a license in the US early next year, and start selling the new drug there.

Gene therapy is generally expensive, but in some cases, due to the long-term effect, the price can be justified and affordable. For example, in the UK, the National Health Service, the NHS, pays for the treatment of hemophilia B, which costs $ 3.5 million per patient.

Professor Sarah Tabrizi says their method is just the beginning and will pave the way for other treatment options that may eventually be more accessible to many people.