A Trial of ONO-2808 in Participants With the Parkinsonian Subtype of Multiple System Atrophy (MSA-P)

A Phase 3, Randomized, Double-blind, Placebo-controlled Study of ONO-2808 in Participants With the Parkinsonian Subtype of Multiple System Atrophy (MSA-P)

The main goal of this clinical trial is to learn if ONO-2808 works to treat adults with the Parkinsonian subtype of Multiple System Atrophy (MSA-P). Researchers will compare ONO-2808 to a placebo (a look-alike substance that contains no drug) to see if ONO-2808 works to treat MSA-P.

Participants will:

• Take ONO-2808 or placebo orally for up to 48 weeks
• Make visits to the clinic for checkups and tests
• Answer questions about their health throughout the trial.

Study Overview

• Status: Not yet recruiting
• Conditions: Multiple System Atrophy, Parkinson Variant
• Intervention / Treatment: Drug: ONO-2808; Other: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 486
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Clinical Team; Phone Number: 888-724-3274; Email: clinicaltrials@deciphera.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria:

• Participants with a diagnosis of clinically established or clinically probable MSA-P according to the 2022 Movement Disorder Society (MDS) criteria for MSA diagnosis.

• Participants in the early stages of the disease, defined as a maximum of 5 years since the onset of one of the following symptoms associated with MSA-P:

  • Parkinsonism
  • Orthostatic hypotension
  • Urinary dysautonomia
• Participants with an anticipated survival of at least 3 years in the opinion of the Investigator.
• Participants who are able to ambulate without the assistance of another person, defined as the ability to take at least 10 steps and then to turn around and walk at least another 10 steps. Use of assistive devices (eg, walker or cane) is allowed.
• Ability to swallow oral medication and willingness to adhere to the study drug regimen.
• Normal range of laboratory values at screening and baseline, especially liver function tests.
• Participants receiving treatment (including chronic medications, and herbal or dietary supplements) for symptoms associated with MSA must be on a stable dosage for at least 60 days prior to randomization based on the judgment of the Investigator. Participants must not initiate new treatment within 60 days prior to randomization.

Key Exclusion Criteria:

• Participants with the cerebellar subtype of MSA according to the 2022 MDS criteria for MSA diagnosis.
• Female participants who are pregnant, planning to become pregnant during the study, or breastfeeding.
• Participants with a clinically significant or unstable medical or surgical condition other than MSA-P that, in the opinion of the Investigator, might preclude safe completion of the study or might affect the results of the study (eg, pulmonary, cardiovascular [including bradyarrhythmia], macular edema, and significant renal or hepatic dysfunction).
• Neurological diseases/disorders other than MSA-P, such as Parkinson's disease, dementia with Lewy bodies, essential tremor, progressive supranuclear palsy, spinocerebellar ataxia, spastic paraparesis, corticobasal degeneration, or vascular, normal pressure hydrocephalus, pharmacological, or postencephalitic parkinsonism.
• Any abnormalities, other than MSA, found on the centrally read brain MRI that, in the opinion of the Investigator, may constitute a confounder for the study or preclude safe participation.
• Participants with documented liver diseases, cirrhosis, prior drug-induced liver injury (DILI), or ascites or symptoms and signs of encephalopathy due to hepatic dysfunction.

Other protocol-defined inclusion and exclusion criteria apply.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo	Other: Placebo; Matching placebo will be administered to participants orally once daily for 48 weeks.
Experimental: ONO-2808 Low Dose	Drug: ONO-2808; ONO-2808 will be administered to participants orally once daily for 48 weeks.
Experimental: ONO-2808 High Dose	Drug: ONO-2808; ONO-2808 will be administered to participants orally once daily for 48 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change from Baseline in modified United Multiple System Atrophy Rating Scale (mUMSARS) Part I (excluding Item 11) with Collapsed Scoring (0-3)	Baseline, Week 48

Secondary Outcome Measures

Outcome Measure	Time Frame
Change from Baseline in Multiple System Atrophy Quality of Life Scale (MSA-QoL) Motor Subscale Score	Baseline, Week 48
Change from Baseline in Magnetic Resonance Imaging (MRI) Volumetric Assessments	Baseline, Week 48
Change from Baseline in Total United Multiple System Atrophy Rating Scale (UMSARS) Score (Part I and Part II, all items)	Baseline, Week 48
Change from Baseline in mUMSARS Score	Baseline, Week 48
Change from Baseline in MSA-QoL Total Score	Baseline, Week 48
Change from Baseline in Patient Global Impression of Change (PGI-C) Score	Baseline, Week 48
Change from Baseline in Patient Global Impression of Severity (PGI-S) Score	Baseline, Week 48
Change from Baseline in Clinical Global Impression of Change (CGI-C) Score	Baseline, Week 48
Change from Baseline in Clinical Global Impression of Severity (CGI-S) Score	Baseline, Week 48

Collaborators and Investigators

• Sponsor: Ono Pharmaceutical Co., Ltd.
• Collaborators: Deciphera Pharmaceuticals, LLC
• Investigators: Study Director: Clinical Team, Ono Pharmaceutical Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): October 1, 2029
• Study Completion (Estimated): October 1, 2029

Study Registration Dates

• First Submitted: September 13, 2026
• First Submitted That Met QC Criteria: September 13, 2026
• First Posted (Actual): September 17, 2026

Study Record Updates

• Last Update Posted (Actual): September 17, 2026
• Last Update Submitted That Met QC Criteria: September 13, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: MSA; Multiple System Atrophy; Movement Disorder; Parkinson's; Parkinsonism; MSA-P; Parkinsonian Subtype of
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Basal Ganglia Diseases; Primary Dysautonomias; Autonomic Nervous System Diseases; Movement Disorders; Parkinson Disease; Multiple System Atrophy; Parkinsonian Disorders
• Other Study ID Numbers: ONO-2808-03-001

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