Gene therapy has delivered a major breakthrough in the fight against Huntington’s disease, with researchers reporting for the first time that genetic modification can significantly slow the progression of the fatal brain disorder.
Biotech firm Uniqure announced results from a long-term trial showing its experimental therapy slowed disease progression by 75% over three years in patients receiving the highest dose. The findings, though not yet published in a peer-reviewed journal, have been hailed as a landmark in neurodegenerative disease research.
The study involved 29 patients with Huntington’s disease, a genetic condition caused by mutations in the huntingtin gene that lead to toxic protein clumps in the brain. These aggregates damage nerve cells, particularly in the striatum, which regulates movement, motivation, and decision-making. Symptoms worsen over time, leading to severe physical and cognitive decline, and no current treatments can alter the disease course.
Patients in the trial underwent a 12- to 15-hour surgical procedure in which surgeons drilled into the skull to deliver the therapy directly to the striatum. The treatment used an inactivated viral vector to deliver DNA coding that switches off production of the defective huntingtin protein.
Of the participants, 17 received a high dose of the therapy and showed a dramatic slowing of disease progression compared with a large group of untreated patients tracked separately. In contrast, 12 patients given a lower dose showed no significant change, though some symptoms improved.
“I was blown away when I saw all of the data and it was very, very clear that the gene therapy worked,” said Dr. Sarah Tabrizi, director of the University College London Huntington’s Disease Centre and lead investigator of the study. “I have never seen anything that shows that level of benefit.”
Biological markers reinforced the clinical findings. Levels of neurofilament—a protein released by damaged neurons—usually rise 30% to 45% in the early years of Huntington’s. In the treated group, however, levels fell, in some cases below baseline. “That tells you that neurons are being saved,” Dr. Tabrizi explained.
The results are prompting researchers to consider whether treating patients earlier could prevent the disease’s most devastating symptoms. The current trial involved people at Stage II or III, but future studies may target those at Stage 0 or I, before symptoms emerge.
Uniqure’s chief executive, Matt Kapusta, described the therapy as “transformational,” adding that slowing the disease offers patients and families “priceless” extra time together. The company plans to seek accelerated approval from the U.S. Food and Drug Administration in early 2026, aiming to make the treatment available later that year.
If approved, it would mark the first disease-modifying therapy for Huntington’s, offering new hope to thousands of families worldwide.