March 30, 2026

Dear ALS community,

We are delighted to share that a new global, pivotal Phase 3 clinical trial, called PREVAiLS, studying the investigational drug pridopidine, has enrolled its first participant.

The study aims to evaluate efficacy and safety of pridopidine in slowing ALS progression in early, rapidly progressive participants. This homogenous population provides the potential to show any treatment effect within the confines of a 48-week clinical trial. Please note that pridopidine is still an investigational drug and is not yet approved by regulatory authorities. Its safety and effectiveness in ALS are still being studied.

This global study plans to include around 500 people and will take place at up to 60 ALS centers worldwide, including sites in the United States, Canada, Europe, the United Kingdom, and Israel.

PREVAiLS is a 48-week randomized (3:2 pridopidine:placebo), placebo-controlled study, with a 48-week open label extension phase to follow. The study seeks to enroll participants with definite or probable ALS (El Escorial Criteria) who are within 18 months from first onset of disease symptoms. The primary endpoint of PREVAiLS is the change from baseline in ALSFRS-R adjusted for mortality at 48 weeks. Secondary and exploratory endpoints include survival and measures of speech, respiratory function, bulbar function and quality of life, as well as patient-reported outcomes of communication and plasma biomarkers. The study will also evaluate the safety and tolerability of pridopidine.

People interested in learning more about the study and participating sites can find details on ClinicalTrials.gov (NCT07322003). The trial is also expected to be listed soon on the EU clinical trials register (EU CT Number: 2025-524002-16-00).

Kind regards,

The Prilenia and Ferrer PREVAiLS team