A new kind of gene therapy could significantly slow the progression of Huntington’s disease with a single operation, according to one of the researchers behind the discovery.
“I keep having to check that I’m not dreaming,” University College London neuroscientist Edward Wild told CTV Your Morning in a Thursday interview. “This is the first time anything has worked to slow the progression of (Huntington’s).”
Huntington’s disease is a rare and debilitating neurological condition that impairs the patient both cognitively and physically, alongside psychiatric symptoms.
The condition is not considered fatal in and of itself, but symptoms typically worsen over time, requiring round-the-clock care in later stages as patients lose the ability to move, eat and bathe, unassisted. Patients can die of complications of the illness, with an average life expectancy of between 10 and 30 years after diagnosis.
Roughly 6,000 Canadians are living with the disease, with another 7,500 at risk of developing it in their lifetime. Huntington’s is a genetic condition, with symptoms typically first appearing between the ages of 35 and 55.
Historically, treatments have involved managing a patient’s symptoms, such as medications for psychosis and movement disorders, but the condition has long been considered to have no cure.
“Huntington’s is a ticking time bomb,” said McGill University neurologist Massimo Pandolfo in a release last year. “If one of your parents had it, you have a 50 per cent chance of inheriting the mutated gene for it. And if you have the mutated gene, then you will develop the disease.”
‘Beyond our wildest dreams’
Though previously incurable, the cause behind Huntington’s disease has been understood for more than three decades: A genetic mutation that causes the brain to produce dangerously defective proteins that kill neurons.
That flaw in the DNA, passed down from parent to child, spirals out into a devastating array of symptoms, from uncontrolled movement and incontinence, to mood swings, to dementia.
The new treatment from Wild and his team aimed to “reprogram” that process in the brain.
Over the course of a 12-hour operation, neurosurgeons inject the patient with a virus designed to instruct neurons to make less of the harmful proteins. Clinical trials have shown the gene therapy can slow disease progression by 75 per cent, three years on from the procedure.
Wild says that patients with Huntington’s could live years or decades longer with a high quality of life, and if the treatment is administered before symptoms set in, possibly delaying or even preventing the onset entirely.
The treatment will require review and approval by federal regulators before it sees regular use, but Wild underscored the significance of this step along the path.
“The fact that it’s a 75 per cent slowing of progression, with the first thing that works, is just beyond our wildest dreams,” he told CTV.
“We could end up in a situation where, for the first time, our patients can look forward to a healthy, happy old age.”
