NCT07322003 · Prilenia
Pridopidine Phase 3 Study to Evaluate Efficacy and Safety in ALS
(PREVAiLS)
What this study is about
The goal of this clinical trial is to learn if the drug pridopidine works to treat amyotrophic lateral sclerosis in adults. It will also help to learn about the safety of pridopidine.
View original scientific description
The goal of this clinical trial is to learn if the drug pridopidine works to treat amyotrophic lateral sclerosis in adults. It will also help to learn about the safety of pridopidine. The main question it aims to answer is: Does pridopidine slow disease progression of ALS? Researchers will compare pridopidine to a placebo (a look-alike substance that contains no drug) to see if pridopidine works to treat ALS. Participants will: Take pridopidine or a placebo by mouth every day for 48 weeks. Afterwards, all participants will take pridopidine for another 48 weeks.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Definite ALS or Probable ALS using the El Escorial criteria.
- Symptom onset of ≤18 months at screening.
- Slow vital capacity (SVC) greater or equal to 60% predicted.
- Treatment Research Initiative to Cure ALS (TRICALS) Risk Profile Calculator score, based on the European Network for the Cure of ALS (ENCALS) survival prediction model, in the range of -6 to -2, inclusive, at screening.
- Able to swallow a capsule. Key
Exclusion criteria
- Presence of tracheostomy or permanent assisted ventilation.
- Clinically significant heart disease, clinically significant history of arrhythmia, symptomatic or uncontrolled atrial fibrillation despite treatment, or asymptomatic sustained ventricular tachycardia, or presence of left bundle branch block.
- Presence of unstable psychiatric disease, cognitive impairment, dementia or substance abuse that would impair ability of the participant to provide informed consent and participate in the study.
- Clinically significant and/or unstable medical condition (other than ALS) that may either pose a clinically meaningful risk to the participant and/or to study completion.
- Use of medications that prolong QT interval.
- Previous treatment with pridopidine, gene therapy, or antisense oligonucleotides.
- Confirmed mutation in the SOD1, FUS or C9orf72 gene.
Where
- San Francisco, California
- Jacksonville, Florida
- Tampa, Florida
- Atlanta, Georgia
- Chicago, Illinois
- Fairway, Kansas
- Boston, Massachusetts
- St Louis, Missouri
- Lincoln, Nebraska
- New York, New York
- Philadelphia, Pennsylvania
- Dallas, Texas
And 2 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 8, 2026 · Source of record for eligibility and locations