RNA Therapy Lowers Protein Linked to Huntington’s Disease
A Phase 1b clinical trial shows that brezosiran significantly reduces mutant huntingtin protein levels in patients.
Updated on Oct. 27, 2026 in Alzheimer’s
A new RNA-based therapy called brezosiran reduced mutant huntingtin protein levels by up to 83% in clinical trial participants. The treatment is designed to slow disease progression by preventing the production of harmful protein forms.
Why it matters
Huntington’s disease is a progressive condition, and limiting the production of toxic proteins is a primary strategy for potentially delaying its symptoms. Successful protein reduction could offer a new therapeutic pathway for individuals living with this neurodegenerative disorder.
In a Phase 1b trial involving 48 participants, brezosiran reduced cerebrospinal fluid mutant huntingtin protein levels by a mean of 60% to 64% three months post-injection. Some individuals in the study achieved reductions as high as 83%.
The players
Alnylam Pharmaceuticals
This biopharmaceutical company specializes in the development of RNA interference therapeutics.
Brezosiran
This experimental RNA-based therapy is designed to target the underlying genetic cause of Huntington's disease.
The details
Administered via injection into the spinal canal, the therapy works by shutting down the production of mutant huntingtin protein. During the follow-up period, indicators of nerve damage and brain inflammation remained stable in study subjects.
Timeline
The Phase 1b clinical trial was launched in late 2024.
Results were presented at a research congress from October 22-24, 2026.
A pivotal placebo-controlled study is expected to begin in 2027.
Health Landscape
This development represents a notable step within the ongoing research into RNA interference therapies for neurodegenerative diseases. It follows a pattern of identifying genetic drivers of neurological decline to create targeted molecular interventions.
While the therapy is currently in the trial phase, successful development could eventually offer a new treatment option for Huntington's disease patients to manage disease progression. Future iterations of the drug may involve twice-yearly spinal injections.
The takeaway
Targeting protein production with RNA-based therapies remains a promising frontier for addressing genetically linked neurodegenerative conditions. Patients and families should continue to monitor clinical trial registry updates for opportunities to participate in future research.
What happens next
A pivotal placebo-controlled study for brezosiran is expected to begin in 2027 to further evaluate the drug's safety and efficacy.
Further reading
Learn more about the latest research in the field by visiting our Alzheimer’s section.
