The new drug injected into the spinal cord fluid can apparently lower toxic proteins in the brain.
"We have every reason to believe that if we can treat early to reduce production of the mutant protein that we should be able to produce really meaningful delays in the onset of symptoms".
"But the principle that a gene, any gene affecting disease progression and susceptibility, can be safely modified in this way in humans is very exciting and builds momentum and confidence in pursuing these avenues for potential treatments", she told the BBC. These patients were divided into two groups - one to receive the test drug and the other to receive placebo.
Professor Sarah Tabrizi, director of University College London's Huntington's Disease Centre, who led the trial, said the results were "beyond what I'd ever hoped", and said it eventually may be possible to stop the disease before irreversible damage to the brain had occurred.
"The key now is to move quickly to a larger trial to test whether [it] ... slows disease progression", she said in a statement.
The new drug is created to disrupt the expression of this faulty gene, preventing the production of huntingtin and thus hopefully slowing the onset of the disease.
"For the first time, a drug has lowered the level of the toxic disease-causing protein in the nervous system, and the drug was safe and well-tolerated", Tabrizi said in a release on Monday.
It's hoped this form of drug could be adapted to target proteins in other now incurable brain disorders, such as Alzheimer's disease.
The technique has already led to a drug for spinal muscular atrophy that was approved a year ago.More news: LiAngelo, LaMelo Ball In 'Serious Discussions' With Lithuanian Basketball Team
More news: Pro wrestler arrested after putting wife in headlock
More news: Rick Zamperin: Seattle is nice, but National Hockey League should return to Quebec City
Neuroscientist at UCL, Prof John Hardy said: "If I'd have been asked five years ago if this could work, I would have absolutely said no". "This is probably the most significant moment in the history of Huntington's since the gene [was isolated]".
For instance, Alnylam Pharmaceuticals' own patisiran has driven the company's stock up more than 250% this year thanks to strong, later-stage clinical trial results.
The treatment works by using a synthetic single strand of DNA to attach to the messenger molecule before it forms into a protein capable of destroying brain cells.
The success raises the possibility that a similar approach may even work for other degenerative brain disorders. "You can target any protein".
"Huntington's distant from everyone else is sufficiently energizing", said Hardy, who initially recommended that amyloid proteins assume a focal part in Alzheimer's. One example is tau protein in Alzheimer's disease. "I don't want to do that to them", she told CTV News.
"Much more work is needed but it's a huge, extraordinary result in it's own right".
Finding a cure for any disease is a complex process.
Around 10,000 individuals in the United Kingdom have the condition and around 25,000 are in danger.
'Urea is natural chemical produced by the body that is normally cleared away in our urine, but this study suggests a build-up of urea in the brain could be involved in the development of Huntington's disease.