A Prospective Exploratory Study of the Safety and Preliminary Efficacy of the α-Syn H21 Monoclonal Antibody in Patients With Multiple System Atrophy

NCT07774585 | Not Yet Recruiting Phase 1

• 1 other identifier: H21-MSA
• Study Type: interventional
• Target: 3
• Locations: 1 country
• Sites: 1

Brief Summary

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by autonomic dysfunction, parkinsonism, and cerebellar ataxia. Abnormal aggregation of alpha-synuclein is believed to play an important role in disease progression. The α-Syn H21 monoclonal antibody is designed to selectively bind pathological alpha-synuclein aggregates and may reduce their spread and related neuroinflammation. This single-center, prospective, exploratory study will evaluate the safety, tolerability, and preliminary efficacy of the α-Syn H21 monoclonal antibody in patients with MSA. Participants will receive intravenous infusions of H21 every 4 weeks for 3 doses and will be followed for 12 weeks. Clinical symptoms, laboratory tests, imaging findings, and adverse events will be assessed to determine whether H21 may provide clinical benefit and support future larger studies.

Conditions

Multiple System Atrophy

Outcome Measures

Primary Outcomes (3)

• Incidence of treatment-emergent adverse events

  Incidence, severity, and relationship of adverse events (AEs) and serious adverse events (SAEs) to study treatment.

  From first dose through Week 12

• Change from Baseline in Unified Multiple System Atrophy Rating Scale (UMSARS) Total Score (Parts I-IV)

  Change from baseline in the total score and subscale scores of the Unified Multiple System Atrophy Rating Scale (UMSARS Parts I-IV). The UMSARS is a clinician-administered scale used to assess disease severity in patients with multiple system atrophy. Total scores are derived from Parts I-IV, with higher scores indicating greater disease severity and worse clinical status. The total score ranges from 0 to 249, with higher scores indicating more severe impairment.

  Baseline, Week 4, Week 8, and Week 12

• Change from baseline in DAT-PET/MRI measures of striatal dopamine transporter uptake and brain structural changes

  Change from baseline in DAT-PET/MRI imaging parameters, including brain metabolic and structural changes.

  Baseline and Week 12

Secondary Outcomes (17)

• Change from Baseline in Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Total Score

  Baseline, Week 4, Week 8, and Week 12

• Change in Patient Global Impression of Improvement (PGI-I) Score

  Baseline, Week 4, Week 8, and Week 12

• Change from Baseline in Mini-Mental State Examination (MMSE) Score

  Baseline, Week 4, Week 8, and Week 12

• Change from Baseline in Hamilton Depression Rating Scale (HAMD) Score

  Baseline, Week 4, Week 8, and Week 12

• Change from Baseline in Hamilton Anxiety Rating Scale (HAMA) Score

  Baseline, Week 4, Week 8, and Week 12

Study Arms (1)

H21 Treatment

EXPERIMENTAL

Biological: α-Syn H21 Monoclonal Antibody

Interventions

α-Syn H21 Monoclonal Antibody BIOLOGICAL

The α-Syn H21 monoclonal antibody is a humanized monoclonal antibody designed to selectively bind pathological alpha-synuclein aggregates. Participants will receive the study drug by intravenous infusion once every 4 weeks for a total of 3 doses during the 12-week study period.

H21 Treatment

Eligibility Criteria

• Age: 45 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 45 to 75 years, male or female
• Diagnosis of Multiple System Atrophy meeting current clinical diagnostic criteria for probable or possible MSA
• Disease duration of 2 years or less from onset of motor or autonomic symptoms
• Clinically stable disease without significant fluctuation or acute worsening within 4 weeks before enrollment
• Able to comply with study procedures and follow-up assessments
• Mini-Mental State Examination (MMSE) score not consistent with significant dementia
• Willing and able to provide written informed consent

You may not qualify if:

• History or presence of other neurological disorders that may interfere with study assessments, including Parkinson's disease, progressive supranuclear palsy, corticobasal degeneration, or stroke
• Severe cognitive impairment or psychiatric disorder, including clinically significant depression or anxiety
• Severe cardiac, hepatic, renal, or other major systemic disease
• History of severe hypersensitivity to monoclonal antibody therapies Pregnant or breastfeeding women
• Women or men unwilling to use effective contraception during the study
• Participation in another clinical trial or receipt of investigational treatment within 3 months before enrollment
• Any other condition that, in the investigator's judgment, would make participation inappropriate

Sponsors & Collaborators

• Ruijin Hospital: lead

Study Sites (1)

Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, Shanghai 200025

Shanghai, Shanghai Municipality, 200025, China

Location

MeSH Terms

Conditions

Multiple System Atrophy

Condition Hierarchy (Ancestors)

Primary Dysautonomias; Autonomic Nervous System Diseases; Nervous System Diseases; Basal Ganglia Diseases; Brain Diseases; Central Nervous System Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases

Central Study Contacts

Jun Liu, MD, PhD

CONTACT

021-86-64370045; jly0520@hotmail.com

Yan SHEN, MD, PhD

CONTACT

+86-021-64370045; shenyanzmins@sina.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 12, 2026
• First Posted: August 19, 2026
• Study Start (Estimated): September 15, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: August 19, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)