According to The Guardian, the phase one trial included 46 men and women with early onset Huntington's disease, who were given four spinal injections, one each month, with an increasing dose each time.
Current treatments only help with symptoms, rather than slow the disease.
Muted investor response aside, the results (called "groundbreaking" by lead researcher Sarah Tabrizi of the University College London) prompted Swiss pharmaceutical giant Roche to exercise its licensing option for Ionis-HTTRx.
Prof Giovanna Mallucci, who discovered the first chemical to prevent the death of brain tissue in any neurodegenerative disease, said the trial was a "tremendous step forward" for patients and there was now "real room for optimism".
The treatment could potentially be adapted to target other incurable brain disorders such as Alzheimer's and Parkinson's.
A major unknown was whether the trial would show that IONIS-HTTRx could lower the level of mutant huntingtin protein in the nervous system.
The first symptoms, which typically appear in middle age, include mood swings, anger and depression.
The researchers injected the drug into 46 patients, conducted at the Leonard Wolfson Experimental Neurology Centre at the National Hospital for Neurology and Neurosurgery in London.
Huntington's is caused by an error in a section of DNA called the huntingtin gene. It works by interfering with its ability to cause cells to produce the toxic proteins that damage the brain.
Known as IONIS-HTTRx, the drug does not target the gene itself, but is instead a piece of synthesized genetic code that binds to the piece of messenger RNA that transports the information needed to build huntingtin around the cell.
To deliver the drug to the brain, it must be injected into the fluid around the spine using a needle.
"I am a neuroscientist. The fact that it does work is really remarkable".
Some people die from the disease within decades.
The team used an ultra sensitive assay to measure the concentrations of the protein in the patient's spinal fluid both before and after treatment.
An experimental drug lowered levels of toxic proteins in the brains of people with Huntington's disease, researchers report. "This is probably the most significant moment in the history of Huntington's since the gene [was isolated]".
The trial was too little, and not sufficiently long, to indicate whether patients' clinical manifestations enhanced, however Roche is presently anticipated that would dispatch a noteworthy trial went for testing this.
The hope is that this drug could be the key to slowing and potentially even stopping the debilitating disease in its tracks. "They may simply require a heartbeat each three to four months", she said.
"You know the last day was better than the next one's going to be".
An global research team led by Professor Russell Snell and Dr Renee Handley from the University of Auckland's School of Biological Sciences, Centre for Brain Research, have identified elevated levels of the chemical urea in the brain of a transgenic sheep model which matches those of human brains affected by Huntington's.
The unexpected success raises the tantalising possibility that a similar approach might work for other degenerative brain disorders.