What's Happening?
Prilenia Therapeutics has announced the publication of Phase 3 trial data on pridopidine in the journal Nature Medicine. The study, known as PROOF-HD, focused on early-stage Huntington's disease (HD) patients not taking antidopaminergic medicines (ADMs). The trial demonstrated that pridopidine slowed clinical progression and maintained function, cognition, and motor performance in these patients. Although the study did not meet its primary or secondary endpoints in the full population, it showed clinically meaningful improvements in a subgroup of patients. Pridopidine is a sigma-1 receptor agonist that stimulates neuroprotective mechanisms impaired in neurodegenerative diseases like HD and ALS. The drug has shown a favorable safety and tolerability profile in its extensive development program involving approximately 1,600 participants.
Why It's Important?
The publication of these findings is significant as it represents the first Phase 3 trial in Huntington's disease to deliver consistent benefits across multiple clinical domains, including cognition and motor performance. This development offers hope for a disease-modifying treatment that goes beyond symptom control, potentially slowing the progression of HD. The results could pave the way for global regulatory approval and provide a new therapeutic option for patients who currently have limited treatment choices. The study's findings also highlight the importance of patient selection and the impact of ADM exposure, which can confound treatment effects.
What's Next?
A planned confirmatory study in early HD patients is expected to start next year, aiming to confirm pridopidine's effects and support global regulatory discussions. This study will refine patient selection and dosage strategies to control for confounding factors like ADM exposure. Prilenia and Ferrer are also planning a Phase 3 trial for ALS, building on findings from the Phase 2 HEALEY ALS Platform Trial. Pridopidine has received Orphan Drug designation in HD and ALS in the US and EU, and FDA Fast Track designation for HD treatment.
