Amyloid Monoclonal Antibody Treatment in PD Patients With Coexistent AD Pathology

Efficacy of Lecanemab in Patients With Parkinson's Disease With Coexistent Alzheimer's Disease

This study aimed to determine the efficacy of amyloid clearance of lecanemab in patients with Parkinson's disease (PD) with amyloid co-pathology. Lecanemab, an anti-amyloid monoclonal antibody, was apporoved by the US FDA in July 2023 and in South Korea in May 2024, as a disease-modifying therapy based on its clinical efficacy and reduction of amyloid plaques in patients with early-stage Alzheimer's disease (AD). AD pathology is also common in PD, and approximately 35% of patients with PD dementia have co-existing AD pathology. Currently, no mediations have been developed to slow the progression of PD. Therefore, this study aimed to determine whether reducing the amyloid burden in patients with PD with co-exsistent AD pathology could potentially slow disease progression. To test it, patients with PD with mild cognitive impairment or early dementia, who were confirmed to have amyloid deposition through amyloid imaging, would be enrolled as a treatment arm, and the degree of reduction of amyloid plaque after 18 months of lecanemab administration would be investigated.

Study Overview

• Status: Not yet recruiting
• Conditions: Parkinson Disease
• Intervention / Treatment: Drug: Lecanemab; Other: Lecanemab non-administration group

Detailed Description

This study plans to consecutively enroll the patients with Parkinson's disease (PD) who have confirmed amyloid deposition on amyloid imaging and meet the indications for lecanemab administration. After a thorough explanation of lecanemab administration, patients who consent to the treatment would be enrolled. Patients assinged to the treatment arm would receive standard lecanemab treatment (10mg/kg intravenous infusion every two weeks for 18 months) and standard PD care. Patients who do not consent to the administration of lecanemab would receive stadnard care for PD and be monitored their progress without any further intervention.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Phil Hyu Lee, MD; Phone Number: 82-2-2228-1608; Email: phlee@yuhs.ac

Study Locations

• South Korea
  • Seoul, South Korea
    • Yonsei University College of Medicine
    • Contact: Phil Hyu Lee, MD; Phone Number: +82-2-2228-1608; Email: phlee@yuhs.ac

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Patients diagnosed with Parkinson's disease
2. Amyloid deposition confirmed by FBB PET
3. Mild cognitive impairment or early dementia (CDR 0.5 or 1) on neuropsychological tests
4. Adults aged 50-90 years

Exclusion Criteria:

1. Cases in which lecanemab administration is contraindicated (based on recommendations from the Korean Dementia Association)
2. Cases in which neuropathologies other than Parkinson's disease or Alzheimer's disease are suspected as the underlying disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Lecanemab admnistration group; Patients who receive lecanemab 10mg/kg every two weeks for 18 months	Drug: Lecanemab; Patients assigned to this arm receive lecanemab 10mg/kg intravenously every two weeks for 18 months.
Active Comparator: Lecanemab non-admnistration group; Patients who do not receive lecanemab	Other: Lecanemab non-administration group; Patients assigned to this arm do not receive lecanemab 10mg/kg intravenously during the follow-up period

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in amyloid dposition on amyloid imaging scans	Changes in amyloid dposition (i.e., global FBB SUVR) on amyloid imaging scans (18F-FBB PET) after lecanemab administration in the lecanemab adminstration group	Change from baseline to 18 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
longitudinal changes in the MMSE score	The change in Mini-Mental State Examination (MMSE) score from baseline to 18 months will be compared between the lecanemab administration group and the non-administration group.	Change from baseline to 18 months
longituidnal changes in UPDRS-III scores.	The change in Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) score from baseline to 18 months will be compared between the lecanemab administration group and the non-administration group.	Change from baseline to 18 months
Longitudinal changes in the plasma and cerebrospinal fluid biomarkers	Longitudinal changes in the plasma and cerebrospinal fluid biomarkers regarding the Alzheimer's disease in the lecanemab administration group.	Change from baseline to 18 months
longitudinal changes in the MoCA score.	The change in Montreal Cognitive Assessment (MoCA) score from baseline to 18 months will be compared between the lecanemab administration group and the non-administration group.	Change from baseline to 18 months
longitudinal changes in CDR-SB.	The change in Clinical Dementia Rating-Sum of Boxes (CDR-SB) score from baseline to 18 months will be compared between the lecanemab administration group and the non-administration group.	Change from baseline to 18 months
longituidnal changes in composite scores of each cognitive domain.	The change in composite scores of cognitive domains from baseline to 18 months will be compared between the lecanemab administration group and the non-administration group.	Change from baseline to 18 months
longituidnal changes in levodopa-equivalent doses per body weight [mg/kg].	The change in levodopa-equivalent dose (LED) from baseline to 18 months will be compared between the lecanemab administration group and the non-administration group.	Change from baseline to 18 months

Collaborators and Investigators

• Sponsor: Yonsei University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): June 1, 2030
• Study Completion (Estimated): November 1, 2030

Study Registration Dates

• First Submitted: December 21, 2025
• First Submitted That Met QC Criteria: April 15, 2026
• First Posted (Actual): April 22, 2026

Study Record Updates

• Last Update Posted (Actual): April 22, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: amyloid; Parkinson disease; lecanemab
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Neurocognitive Disorders; Dementia; Tauopathies; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Alzheimer Disease; Parkinson Disease; lecanemab
• Other Study ID Numbers: 4-2025-1358

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: No
• Studies a U.S. FDA-regulated device product: No