In a groundbreaking first, a gene therapy in clinical trials has slowed the progression of Huntington's disease, a rare genetic disorder in which toxic bits of protein cause brain cells to malfunction and die.

To date, approved treatments for Huntington's disease aim to manage its symptoms, which most often emerge in a person's 30s or 40s. The progressive condition injures and kills key neurons involved in controlling mood, cognition and motor control. Various drugs can help to offset the depression, hallucinations and poorly coordinated movements that arise from that destruction.

Now, in trial results shared Wednesday (Sept. 24), scientists announced that a new gene therapy called AMT-130 appears to slow the disease's progression — marking a first for the field.

"These groundbreaking data are the most convincing evidence in the field to date and underscore the disease-modifying effect in Huntington's disease, where an urgent need persists," Dr. Sarah Tabrizi, the lead scientific advisor on the trial and the director of the University College London (UCL) Huntington's Disease Centre, said in a statement. "For patients, AMT-130 has the potential to preserve daily function, keep them in work longer, and meaningfully slow disease progression."