Alnylam reports up to 83% huntingtin reduction
Key points
- Alnylam Pharmaceuticals reported initial Phase 1b results for brezosiran (ALN-HTT02), showing mean reductions of 60%–64% in cerebrospinal fluid mutant huntingtin protein after three months at the highest dose evaluated.
- Individual reductions reached 83%, while early safety findings showed no dose-dependent increases in monitored inflammatory markers, neurofilament light chain or brain ventricular volume.
- Alnylam plans to initiate a placebo-controlled pivotal Huntington's disease trial in 2027, subject to regulatory alignment, and will discuss the program at its October 26 RNAi Roundtable.
Alnylam Pharmaceuticals (NASDAQ:ALNY) reported initial Phase 1b results showing that brezosiran reduced cerebrospinal fluid mutant huntingtin protein by an average of 60%–64% after three months in the highest dose group evaluated.
Individual protein reductions reached 83%, with dose-dependent effects observed across five treatment cohorts and confirmed using two independent assays.
“The deep and durable mutant huntingtin lowering observed after a single dose, together with the encouraging safety profile seen to date, give us confidence to advance brezosiran into a pivotal study,” said Alnylam Chief Research and Development Officer Pushkal Garg.
Participants followed for up to 12 months showed no dose-dependent increases in cerebrospinal fluid inflammatory markers, neurofilament light chain or brain ventricular volume.
Alnylam plans a placebo-controlled pivotal trial in 2027, pending regulatory alignment, to assess whether brezosiran can slow Huntington's disease progression.
The investigational RNA interference therapy targets both full-length mutant huntingtin and the shorter mutant HTT1a protein, with the company exploring twice-yearly dosing.
Eligible participants can enter a 36-month open-label extension receiving treatment every six months, while Alnylam has scheduled an RNAi Roundtable for October 26, 2026.
Frequently asked questions
More from United States
Lamar raises 2026 AFFO outlook to $8.97
Lemonade posts $336 million Q3 revenue, narrows loss
BD reveals $5.27 billion Q4 revenue, raises 2027 outlook
Cummins earnings surge to $1.14 billion as sales climb 13%
Six Flags reveals $1.17 billion Q3 revenue amid $366 million loss
EPAM Systems reports $1.43B Q3 revenue, expands buyback to $1.8B
