The first drug that aims to treat Huntington's disease is set to be tested in human clinical trials.
The medicine is the first of its kind to focus on the cause of the debilitating neurological disease and has been proven safe and effective in animal models.
The Potential Wonder Drug
The new medicine called IONIS-HTTRx is classified as an antisense drug, which works by inactivating the protein causing the disease. Simply put, the drug acts as a "gene silencer" that bars the so-called huntingtin protein that is found in patients with Huntington's disease.
"It is very exciting to have the possibility of a treatment that could alter the course of this devastating disease," says study principal author Dr. Blair Leavitt from the University of British Columbia in Vancouver, Canada. He adds that the only existing treatments for Huntington's disease patients center on alleviating signs and symptoms.
Success In Animal Models
The researchers first tested the drug in mice and monkey models.
For the mice models with Huntington's Disease, the scientists discovered that antisense drugs hold disease progress and lead to the continued shift of the disease's features that results from the interaction of its genotype and the environment.
Particularly, mice models subjected to have Huntington's disease show improvements within one month of treatment. The subject returned to normal two months following the termination of treatment.
Another group of transgenic mice models of Huntington's disease becomes better two months after the start of the antisense therapy. The said improvement lasted for at least nine months after the treatment was stopped.
In monkeys, the authors administered antisense drug into the spinal canal. As a result, they observed declines in huntingtin mRNA and protein in the entire central nervous system, depending on the dose injected.
They were also able to see a 50 percent decrease in huntingtin levels in the cerebral cortex, which is the outer layer of the brain's tissues.
In both the mice and monkey models, IONIS-HTTRx did not cause any unwanted side effects and the subjects tolerated the drugs well.
The animal model study will be presented at the 68th Annual Meeting of the American Academy of Neurology in Canada this coming April.
The success of the animal trials will now be applied to humans. The drugs will also be administered in the spinal canal of human subjects as the drug cannot pass through the blood-brain barrier.
At present, the medicine is given in four doses at monthly intervals, but the researchers will study different drug doses for safety.
In human trials, the researchers will also look into the different actions and effects of the drug on particular disease indicators. They will also ascertain clinical outcomes.
With all these procedures, Leavitt says it may take several more years to be put the drug in human clinical practice.
Huntington's disease is a rare neurological disorder characterized by uncontrolled movements, emotional challenges and intellectual impairments.
The disease is hereditary and may be passed on from a parent with huntingtin gene to their offspring. A child with a huntingtin-carrier parent has a 50/50 chance of inheriting the gene. If the gene is indeed inherited, that person is bound to develop Huntington's disease.