Prilenia Therapeutics and Ferrer have enrolled the first participant in the pivotal Phase III PREVAiLS clinical trial assessing pridopidine in individuals with rapidly progressive amyotrophic lateral sclerosis (ALS) early in disease progression.
The enrolment took place at Mass General Brigham, overseen by MGH Neurological Clinical Research Institute co-director and PREVAiLS principal investigator Sabrina Paganoni.
The study is based on data from a subgroup analysis of participants with rapidly progressive ALS early in their disease course, observed in the Phase II HEALEY ALS platform trial.
While the HEALEY trial did not reach its primary or secondary endpoints overall, analyses indicated effects among those with rapid progression, which PREVAiLS aims to confirm.
The PREVAiLS study will be conducted at up to 60 ALS centres throughout 13 countries.
For this trial, 11 sites have already been initiated or are set to begin soon, with further recruitment expected at additional sites in the European Union, Canada, the UK, Israel, and the US over the next few months.
It is structured as a 48-week randomised (three to two pridopidine to placebo), placebo-controlled study with a subsequent 48-week open-label extension.
Participants must have definite or probable ALS per El Escorial Criteria and be within 18 months of symptom onset.
The primary endpoint is the change from baseline in the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised (ALSFRS-R) adjusted for mortality at 48 weeks.
Secondary and exploratory outcomes include survival, speech and respiratory function, bulbar measures, quality of life and biomarkers.
The therapy has demonstrated a favourable safety profile in over 1,600 participants, some of whom have been treated for up to seven years.
Paganoni said: “Pridopidine is a sigma-1 receptor (S1R) agonist. The S1R has been shown to play a role in stimulating multiple neuroprotective pathways impaired in neurodegenerative diseases such as ALS and Huntington’s disease.
“Enrolling the first participant in this confirmatory study is a milestone in our search for potential new therapeutic options that may help to slow disease progression, preserve function, maintain speech and prolong survival – key aims of early ALS therapy.”
In December 2025, the US Food and Drug Administration granted clearance to Prilenia Therapeutics and Ferrer to commence a Phase III trial of pridopidine in individuals with rapidly progressive ALS at an early stage of disease.
