A drug which appears to reverse Huntington’s disease is being trialled in humans after proving successful in monkeys and mice.

The new drug, called IONIS-HTTRx, silences the gene known to be responsible for the production of a protein which causes Huntington’s.

The disease is a hereditary condition which damages nerve cells in the brain and effects around 7,000 people in Britain. It causes uncontrolled movements, loss of intellectual abilities, emotional problems and eventually death.

"It is very exciting to have the possibility of a treatment that could alter the course of this devastating disease"

Dr Blair Leavitt, University of British Columbia

Now scientists have shown that it is not only possible to halt the disease but to reverse the damage.

"It is very exciting to have the possibility of a treatment that could alter the course of this devastating disease," said clinical study principal investigator Dr Blair Leavitt, of the University of British Columbia in Vancouver.

"Right now we only have treatments that work on the symptoms of the disease."

Huntington’s is caused by a mutated HTT gene, and everyone who inherits the genetic defect will eventually develop the disease.

Researchers have been trying to develop a drug which acts like a dimmer switch, turning the gene down so that it can no longer produce the devastating protein which causes brain damage.

Huntington's damages the brain  Photo: Alamy

When they tested IONIS-HTTRx on mice with the disease their motor function improved within a month and within two months their health was restored to normal. In monkeys the drug was found to decrease the HTT protein throughout the central nervous system by 50 per cent.

The drug is delivered into the cerebral spinal fluid via lumbar injection, as antisense drugs do not cross the blood brain barrier – a protective sheath that prevents toxins entering the brain.

The drug is now being trialled in humans in low doses to check that it is safe for larger trials into its efficacy to begin.

The research was presented at the American Academy of Neurology's 68th Annual Meeting in Vancouver, Canada, April 15 to 21, 2016.