Can a failed ALS drug help PSP patients? new trial results are in

NCT ID NCT06122662

Completed Disease control Sponsor: Amylyx Pharmaceuticals Inc. Source: ClinicalTrials.gov ↗

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This completed Phase 2b/3 trial tested the drug AMX0035 in 139 people with progressive supranuclear palsy (PSP), a rare brain disease that causes problems with balance, movement, and thinking. The study compared the drug to a placebo to see if it could slow the disease. The results will help determine if AMX0035 is safe and effective enough to pursue as a treatment for PSP.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: AMX0035 (a combination of sodium phenylbutyrate and taurursodiol)
What this could lead to: If successful, AMX0035 could slow the progression of PSP, a rare and devastating brain disease, giving patients more time with better function.
What could go wrong: This is an early-to-mid-stage trial with only 139 participants. The drug may not show a meaningful benefit, and side effects could limit its use. Previous trials of AMX0035 for ALS failed to confirm benefit.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Get updates

Get notified about this study

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

familial spontaneous pneumothorax neurodegenerative disease progressive supranuclear palsy

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

ATYPICAL PARKINSONISM NEURODEGENERATIVE DISEASES PROGRESSIVE SUPRANUCLEAR PALSY PSP

Contacts and locations

Locations

Asklepios Fachklinikum Stadtroda

Stadtroda, Thuringia, 7646, Germany
Augusta University

Augusta, Georgia, 30912, United States
Azienda Ospedale-Università di Padova

Padova, 35128, Italy
Azienda Ospedaliera Universitaria OO. RR. S. Giovanni di Dio e Ruggi D'Aragona

Salerno, 84131, Italy
Azienda Ospedaliera Universitaria Policlinico Umberto I - Università di Roma La Sapienza

Roma, 185, Italy
Baylor College of Medicine

Houston, Texas, 77030, United States
CHU Rennes - Hopital Pontchaillou

Rennes, Ille Et Vilaine, 35033, France
CHU de Limoges - Hôpital Dupuytren

Limoges, Haute Vienne, 87042, France
Cedars Sinai Medical Center

Los Angeles, California, 90048, United States
Central Texas Neurology Consultants

Round Rock, Texas, 78681, United States
Cleveland Clinic Lou Ruvo Center for Brain Health

Las Vegas, Nevada, 89106, United States
Clinica Universidad de Navarra

Pamplona, Navarre, 31008, Spain
Fondazione IRCCS CA' Granda Ospedale Maggiore Policlinico

Milan, 20122, Italy
Fondazione IRCCS Istituto Neurologico Carlo Besta

Milan, 20133, Italy
Fondazione Policlinico Universitario Agostino Gemelli IRCCS

Roma, 168, Italy
Groupe Hospitalier Pellegrin - Hôpital Pellegrin

Bordeaux, Gironde, 30076, France
Groupe Hospitalier Pitie-Salpetriere

Paris, 75013, France
Hopital Caremeau

Nîmes, Gard, 30029, France
Hopital Roger Salengro - CHU Lille

Lille, Nord, 59037, France
Hospital Clinic de Barcelona

Barcelona, 8036, Spain
Hospital Universitari i Politecnic La Fe

Valencia, València, 46026, Spain
Hospital Universitario Ramon y Cajal

Madrid, 28034, Spain
Hospital Universitario Virgen del Rocio

Seville, 41013, Spain
Hospital Universitario de La Princesa

Madrid, 28006, Spain
Hospital de Cruces

Barakaldo, Bizkaia, 48903, Spain
Hôpital de la Timone

Marseille, Bouches-du-Rhône, 13385, France
Kerwin Medical Center

Dallas, Texas, 75231, United States
Klinikum der Universität München

Munich, Bavaria, Germany
Krankenhaus Agatharied

Hausham, Bavaria, 83734, Germany
Lahey Hospital and Medical Center

Burlington, Massachusetts, 01805, United States
Massachusetts General Hospital

Boston, Massachusetts, 02114, United States
Mayo Clinic

Scottsdale, Arizona, 85259, United States
Mayo Clinic - Rochester

Rochester, Missouri, 55905, United States
Mayo Clinic Florida

Jacksonville, Florida, 32224, United States
Medical University of South Carolina (MUSC)

Charleston, South Carolina, 29425, United States
Northwestern University PD and Movement Disorders Center

Chicago, Illinois, 60611, United States
Ochsner Medical Center

New Orleans, Louisiana, 70121, United States
Oregon Health & Science University

Portland, Oregon, 97239, United States
Paracelsus-Elena-Klinik Kassel

Kassel, Hesse, 34128, Germany
Parkinson's & Movement Disorder Institute

Fountain Valley, California, 92708, United States
Parkinson's Disease and Movement Disorders Center of Boca Raton

Boca Raton, Florida, 33486, United States
Parkinsons and Movement Disorder Center at the Queens Medical Center

Honolulu, Hawaii, 96813, United States
Pennsylvania Hospital

Philadelphia, Pennsylvania, 19107, United States
Quest Research Institute

Farmington Hills, Michigan, 48334, United States
Stanford Movement Disorder Center

Palo Alto, California, 94304, United States
The Cleveland Clinic Foundation

Cleveland, Ohio, 44195, United States
UC Health Anschutz Outpatient Pavilion Anschutz Medical Campus

Aurora, Colorado, 80045, United States
UF Health Dorothy Mangurian Neuroimaging Suite

Gainesville, Florida, 32608, United States
Universitaetsklinikum Carl Gustav Carus TU Dresden

Dresden, Saxony, 1307, Germany
Universitaetsklinikum Duesseldorf AoeR

Ulm, Baden-Wurttemberg, 89081, Germany
Universitaetsklinikum Ulm

Ulm, Baden-Wurttemberg, 89081, Germany
University of Arkansas for Medical Sciences

Little Rock, Arkansas, 72205, United States
University of California, San Francisco (UCSF)

San Francisco, California, 94158, United States
University of Cincinnati

Cincinnati, Ohio, 45219, United States
University of Kansas Medical Center Research Institute, Inc.

Kansas City, Kansas, 66160, United States
University of Kentucky Medical Center

Lexington, Kentucky, 40536-0274, United States
University of Minnesota, CTSI

Minneapolis, Minnesota, 55414, United States
University of Southern California

Los Angeles, California, 90033, United States
University of Utah Movement Disorders Center

Salt Lake City, Utah, 84108, United States
Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States
Veracity Neuroscience, LLC

Memphis, Tennessee, 38157, United States
Virginia Commonwealth University Department of Neurology

Richmond, Virginia, 23298-0059, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.