Phase 3 Pridopidine Trial for ALS Begins Enrollment

A global phase 3 clinical trial of the experimental ALS drug pridopidine has begun, with the first participant enrolled at Mass General Brigham under lead investigator Dr. Sabrina Paganoni, co‑director of Mass General Hospital’s Neurological Clinical Research Institute. The PREVAiLS trial, sponsored by Prilenia Therapeutics and Ferrer, will recruit about 500 patients with early, rapidly progressive ALS at up to 60 treatment centers in 13 countries to test whether the sigma‑1 receptor agonist can safely slow functional decline, preserve speech and prolong survival. This confirmatory study follows a prior phase 2 HEALEY ALS Platform Trial in which pridopidine failed its primary endpoint over 24 weeks but showed signs of benefit in an early, fast‑progressing subgroup, and the drug was generally well tolerated with side effects overlapping common ALS symptoms. Paganoni stresses that PREVAiLS incorporates key design lessons from that earlier work and is currently believed to be the only actively recruiting phase 3 ALS study, though definitive conclusions must wait until data collection and analysis are complete. ALS Association research chief Kuldip Dave says the launch underscores an “urgent need” for new therapies, noting that earlier diagnosis and treatment offer the best chance to preserve patients’ function and quality of life while the community pushes toward a cure.