Study summary

Pridopidine did not beat placebo in its main analysis

PROOF-HD trial (pridopidine) · Phase 3 · Published September 2025, Nature Medicine

-0.11difference in cUHDRS vs placebo (not significant)

What was tested

Pridopidine, a pill that activates the sigma-1 receptor to protect nerve cells, against placebo, in early manifest Huntington disease.

What they found

Neither functional capacity nor the composite cUHDRS score differed significantly from placebo (difference -0.11).
A subgroup not taking antidopaminergic drugs showed a consistent trend favoring pridopidine.
Safety was favorable.

What it means

A new phase 3 (PRECISE-HD) now tests pridopidine in the subgroup that appeared to benefit.

Nat Med, via PubMed ↗ ← Back to the outlook

Last reviewed 2026-11-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.