A Study to Assess the Efficacy, Safety, and Pharmacokinetics of FNP-223 to Slow Progression of Progressive Supranuclear Palsy (PSP)

October 13, 2025 updated by: Ferrer Internacional S.A.

A Randomized, Double-blind, Placebo-controlled, Phase 2 Study to Assess the Efficacy, Safety, and Pharmacokinetics of FNP-223 (Oral Formulation) to Slow the Disease Progression of Progressive Supranuclear Palsy (PSP) (PROSPER)

PROSPER trial is a trial to assess the efficacy of FNP-223 in slowing disease progression in participants with PSP as measured by the PSP Rating Scale (PSPRS) over 52 weeks and to assess the safety and tolerability of FNP-223 for 52 weeks in participants with PSP.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

241

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Bordeaux, France, 33076
        • Groupe Hospitalier Pellegrin
      • Marseille, France, 13005
        • Hopital de la Timone
      • Nîmes, France, 30029
        • L'Hôpital Universitaire Carémeau
      • Paris, France, 75013
        • Hôpital Universitaire Pitié Salpêtrière
      • Toulouse, France, 31059
        • Hôpital Pierre-Paul Riquet
  • Germany
      • Beelitz, Germany, 14547
        • Neurologisches Fachkrankenhaus für Bewegungsstörungen/Parkinson
      • Düsseldorf, Germany, 40225
        • Universitatsklinikum Dusseldorf
      • Leipzig, Germany, 04103
        • Universitätsklinikum Leipzig
      • Munich, Germany, 81377
        • Ludwig-Maximilians-Universität München (LMU)
  • Hungary
      • Pécs, Hungary, 7623
        • Pecsi Tudomanyegyetem Altalanos Orvostudomanyi Kar
  • Italy
      • Bologna, Italy, 40139
        • IRCCS Istituto delle Scienze Neurologiche di Bologna
      • Padua, Italy, 35128
        • Azienda Ospedale Università di Padova
      • Pisa, Italy, 56126
        • Azienda Ospedaliero-Universitaria Pisana
      • Roma, Italy, 00163
        • Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) - San Raffaele Pisana
      • Salerno, Italy, 84081
        • Azienda Ospedaliera Universitaria San Giovanni di Dio Ruggi d'Aragona
  • Poland
      • Katowice, Poland, 40-571
        • Neurologia Slaska Centrum Medyczne
      • Warsaw, Poland, 03-242
        • Mazowiecki Szpital Bródnowski w Warszawie
  • Portugal
      • Braga, Portugal, 4710-243
        • Hospital de Braga
      • Torres Vedras, Portugal, 2560-280
        • Campus Neurológico Senior - Torres Vedras
  • Spain
      • A Coruña, Spain, 15006
        • Complejo Hospitalario Universitario A Coruña
      • Badalona, Spain, 08916
        • Hospital Germans Trias i Pujol
      • Barakaldo, Spain, 48903
        • Hospital Universitario Cruces
      • Barcelona, Spain, 08036
        • Hospital Clinic de Barcelona
      • Madrid, Spain, 28034
        • Hospital Universitario Ramon y Cajal
      • Madrid, Spain, 28041
        • Hospital Universitario 12 de Octubre
      • Pamplona, Spain, 31008
        • Hospital Universitario de Navarra
      • Seville, Spain, 41013
        • Hospital Universitario Virgen del Rocio
      • Valencia, Spain, 46086
        • Hospital Universitari i Politecnic La Fe
  • United Kingdom
      • Cambridge, United Kingdom, CB2 3EB
        • University of Cambridge
      • London, United Kingdom, NW1 ePG
        • University College London Hospitals
      • Newcastle, United Kingdom, NE4 5PL
        • Newcastle Upon Tyne Hospitals
      • Southampton, United Kingdom, SO16 6YD
        • University Hospital Southampton
  • United States
    • California
      • Carlsbad, California, United States, 92011
        • The Neurology Center of Southern California - Carlsbad
      • San Francisco, California, United States, 94158
        • UCSF Weill Institute for Neurosciences
    • Colorado
      • Denver, Colorado, United States, 80113
        • Rocky Mountain Movement Disorders Center
    • Florida
      • Miami, Florida, United States, 33136
        • University of Miami Miller School of Medicine
    • Georgia
      • Augusta, Georgia, United States, 30912
        • Augusta University
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital
    • Michigan
      • Farmington Hills, Michigan, United States, 48334
        • Quest Research Institute
    • New York
      • New York, New York, United States, 10032
        • Columbia University Irving Medical Center
      • New York, New York, United States, 10029
        • Robert & John M. Bendheim Parkinson and Movement Disorders Center at Mount Sinai
    • North Carolina
      • Durham, North Carolina, United States, 27705
        • Duke Neurology
    • Tennessee
      • Nashville, Tennessee, United States, 37212
        • Vanderbilt University Medical Center
    • Texas
      • Round Rock, Texas, United States, 78681
        • Central Texas Neurology Consultants

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male or female participants aged 50 to 80 years, inclusive, at the time of informed consent.

  • Diagnosis of possible or probable PSP of the Richardson's Syndrome (PSP-RS) phenotypes according to the Movement Disorders Society's Progressive Supranuclear Palsy (MDS PSP) clinical features criteria. At least 1 (either 1 or both) of the following 2 items must be met:

    1. Vertical supranuclear gaze palsy.
    2. Slowing of vertical saccades AND postural instability with falls within the first 3 years of PSP symptoms.
  • Presence of PSP symptoms within ≤3 years prior to screening.
  • MoCA score ≥23
  • Full 28-item PSPRS score ≤40.
  • Able to ambulate independently or with minimal assistance defined as the ability to take at least 10 steps (stabilization of 1 arm [ie, use of cane]).
  • Body weight range ≥43 kg/95 lbs to ≤120 kg/265 lbs.
  • Reside outside a skilled nursing facility or dementia care facility, except for participants residing in an assisted living facility.
  • Has a caregiver or study partner who will accompany them to the study visits. The caregiver or study partner must be a person who has frequent contact (at least 7 hours per week at 1 time or in different days) with the participant and is able to provide information about the participant's medication and overall condition. Prior to the conduct of any study procedures, the caregiver or study partner must be willing to sign the independent ethics committee (IEC)/institutional review board (IRB) approved informed consent.

Exclusion Criteria:

Non-PSP- RS Movement Disorders or other central nervous system (CNS) Diseases

  • Score of 3 on any functional domain in the PSP-CDS.
  • Participants with known PSP genetic mutation (based on familiar or clinical history).
  • Evidence of other neurological disorder that could explain signs of PSP (eg, Parkinson's disease, Alzheimer disease, etc.).
  • Brain magnetic resonance imaging (MRI) within 1 year of screening consistent with:
  • Primary degenerative diseases other than PSP.

Procedures

  • For the optional substudy only: Contraindication or refusal to undergo 2 lumbar punctures for obtaining CSF.
  • Contraindication or inability to tolerate MRI for screening MRI and volumetric brain MRI assessments throughout the substudy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: FNP-223
Participants will receive FNP-223 orally (PO), 3 times daily (TID).
Drug: FNP-223
Oral tablets
Placebo Comparator: Placebo
Participants will receive matching placebo, PO, TID.
Drug: Placebo
Oral tablets

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline to Week 52 in the PSPRS Outcome
Time Frame: Baseline to Week 52
Baseline to Week 52
Number of Participants Experiencing Treatment-emergent Adverse Events (TEAEs)
Time Frame: Baseline to Week 52
Clinically significant changes in vital signs, clinical laboratory evaluations, physical examinations, and electrocardiogram (ECG) are included in TEAEs.
Baseline to Week 52
Number of Participants Experiencing Serious Adverse Events (SAEs)
Time Frame: Baseline to Week 52
Baseline to Week 52

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline to Week 52 in Clinical Global Impression of Severity Scale (CGI-S)
Time Frame: Baseline to Week 52
Baseline to Week 52
Change From Baseline to Week 52 Participant Global Impression of Severity Scale (PGI-S)
Time Frame: Baseline to Week 52
Baseline to Week 52
Change From Baseline to Week 52 in Caregiver Global Impression of Severity Scale (CaGI-S)
Time Frame: Baseline to Week 52
Baseline to Week 52
Slope of Decline in PSPRS
Time Frame: Baseline to Week 52
Baseline to Week 52
Change From Baseline to Week 52 in Individual Subitems of PSPRS
Time Frame: Baseline to Week 52
Baseline to Week 52
Change From Baseline to Week 52 in Schwab and England Activities of Daily Living Scale
Time Frame: Baseline to Week 52
Baseline to Week 52
Change From Baseline to Week 52 in PSP Clinical Deficits Scale (PSP-CDS)
Time Frame: Baseline to Week 52
Baseline to Week 52
Change From Baseline to Week 52 in Montreal Cognitive Assessment (MoCA)
Time Frame: Baseline to Week 52
Baseline to Week 52
Change From Baseline to Week 52 in PSP Quality of Life Scale (PSP-QoL)
Time Frame: Baseline to Week 52
Baseline to Week 52
Pharmacokinetic characterization of FNP-223
Time Frame: At Week 4 and Week 16
Mean plasma concentration of FNP-223.
At Week 4 and Week 16

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ferrer Internacional S.A.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 23, 2024

Primary Completion (Estimated)

November 1, 2026

Study Completion (Estimated)

November 1, 2026

Study Registration Dates

First Submitted

March 26, 2024

First Submitted That Met QC Criteria

April 3, 2024

First Posted (Actual)

April 9, 2024

Study Record Updates

Last Update Posted (Estimated)

October 15, 2025

Last Update Submitted That Met QC Criteria

October 13, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FNP223-CT-2301

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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