Significant Advancement in Huntington’s Disease Treatment
A recent study indicates that a single gene therapy could significantly delay the progression of Huntington’s disease, potentially marking a pivotal moment for treatment options for this hereditary brain disorder.
In a trial involving 29 participants at early stages of Huntington’s decline, those who received a high dose of the therapy directly administered to their brains experienced a 75% slowdown in disease progression over three years compared to a control group.
Data released recently by uniQure, a gene-therapy firm based in Amsterdam, showed this benefit was statistically notable across various clinical measures. Trial investigators also noted a reduction in a toxic protein associated with neurodegeneration in the spinal fluid of those who underwent treatment. Because of these promising results, uniQure plans to seek regulatory approval for the therapy next year.
“This gene therapy is obviously a big step forward,” remarked Sandra Kostyk, a neurologist at Ohio State University Wexner Medical Center, who participated in the trial. “The data look quite good.” Yet, despite the excitement, she cautioned that while slowing the disease’s advance could provide additional years of autonomy for patients, it does not offer a cure. She also pointed out that the relatively small size of the study means these results, still unpublished, should be regarded as preliminary. “I think we need more time and more data.”
The Nature of Huntington’s Disease
Typically, Huntington’s disease symptoms worsen gradually, usually emerging between ages 35 and 55. What may start as minor coordination issues or forgetfulness can escalate to involuntary movements, mood swings, and significant memory and cognitive decline.
The disorder is driven by repetitive DNA sequences within the huntingtin gene, which leads to the production of a malfunctioning protein that damages brain cells. Currently, there are no treatments targeting the underlying genetic issue, leaving patients to manage only the symptoms.
Initial treatment attempts focused on antisense therapy, which aimed to reduce the production of the harmful huntingtin protein. Early development showed promise, but hopes were dashed in 2021 when a leading candidate faltered in late-stage testing, with participants actually experiencing worse outcomes than those on a placebo.
This setback shifted the focus towards gene therapy, designed as a one-time intervention to silence or modify the problematic gene.
Gene Therapy Approach
UniQure’s gene therapy utilizes a benign virus to deliver a specific RNA sequence, known as microRNA, directly to the affected brain cells. This microRNA is intended to ‘muzzle’ the faulty huntingtin gene and halt the production of the damaging protein by interrupting its molecular instructions. After delivery, the viral instructions remain in the cells, enabling continued production of the therapeutic microRNA. The discovery of microRNAs was honored with a Nobel Prize last year, although no approved treatments have yet emerged from this technology.
Administering the therapy involves a substantial surgical procedure where clinicians use magnetic resonance imaging to precisely position a cannula in the skull, slowly infusing the treatment into the striatum, a brain region heavily affected by Huntington’s disease.
As Kostyk explains, this is not a simple process. Although most individuals tolerated the treatment without significant safety issues, some reported headaches and other complications resulting from the surgery.
Another gene therapy initiative with a similar design and method launched clinical trials earlier this year, developed by biotech company Spark Therapeutics, now part of Roche, a global pharmaceutical company. If approved, both treatments are expected to cost over $1 million per person, raising concerns about accessibility and the potential strain on healthcare systems worldwide.
Moreover, forthcoming gene-editing technologies like CRISPR might also present hurdles regarding access and affordability. Nonetheless, research is ignited with the possibility that uniQure’s therapy could fundamentally change the landscape of Huntington’s disease, offering a new approach to managing this previously untreatable genetic condition.
“This feels like it could be a turning point,” shared Andrew Duker, a neurologist involved in Spark Therapeutics’ trial.
Fink, a neuroscientist at the University of California, Davis, added, “These results are significant; they could really set up Huntington’s as a prime candidate for next-generation treatments.”
