Study summary

A one-time gene therapy slowed Huntington disease progression by about 75% compared with matched patients

AMT-130 gene therapy, 3-year results · Small phase 1/2 studies · Reported 2025; BLA submitted to FDA in 2026 under the accelerated approval pathway

What was tested

AMT-130, a gene therapy injected directly into the brain once during surgery, which lowers production of the harmful huntingtin protein, in early manifest Huntington disease; compared with matched external controls rather than placebo.

What they found

• High-dose patients worsened by 0.38 points on the cUHDRS over 3 years, vs 1.52 in matched external controls (about 75% slowing).
• The comparison was against external data, not a randomized sham group.

What it means

Potentially the first treatment to slow Huntington disease itself, though regulators debated whether the evidence is strong enough.