A Study of LY3439539 in Participants With Alzheimer's Disease

NCT07598370 | Not Yet Recruiting Phase 1

• 2 other identifiers: 18818I9M-MC-ONAA
• Study Type: interventional
• Target: 30
• Locations: 2 countries
• Sites: 7

Brief Summary

The purpose of this study is to see how LY3439539 affects certain proteins found in the spinal fluid of participants with Alzheimer's disease. Participation in the study will last approximately 9 months with visits about once a month.

Conditions

Alzheimer Disease

Keywords

Cognitive Impairment; Neurodegenerative Diseases; Dementia

Outcome Measures

Primary Outcomes (1)

• Change from Baseline in Cerebrospinal Fluid (CSF) Neurofilament Light Chain (NfL)

  Baseline through end of the Follow-up Period (Week 24)

Secondary Outcomes (4)

• Change from Baseline in Phospho-Tau (pTau)

  Baseline through end of the Follow-up Period (Week 24)

• Change from Baseline in Plasma NfL

  Baseline through end of the Follow-up Period (Week 24)

• Pharmacokinetics (PK) Maximum LY3439539 Serum Concentration (Cmax)

  Baseline through end of the Follow-up Period (Week 24)

• PK: Minimum LY3439539 Serum Concentration (Cmin)

  Time Frame: Baseline through end of Follow up Period (Week 24)

Study Arms (1)

LY3439539

EXPERIMENTAL

LY3439539 administered intravenously (IV)

Drug: LY3439539

Interventions

LY3439539 DRUG

Administered IV

LY3439539

Eligibility Criteria

• Age: 50 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Have gradual and progressive change in memory function reported by the participant or informant for 6 months or longer consistent with a diagnosis of dementia due to Alzheimer's disease
• Have a Mini Mental Score Examination score of 16 to 24, inclusive
• Meet plasma pTau criteria, as defined by the sponsor
• Have body mass index within the range of 17 and 32 kilograms per square meter (kg/m²) (inclusive) at screening
• Are women not of childbearing potential and men willing to practice effective contraception throughout the study.
• Have adequate premorbid literacy, vision, and hearing throughout the study duration and able to complete study procedures.
• Have at least 1, and up to 2, study partners who are in frequent contact with the participant (defined as at least 10 hours per week).

You may not qualify if:

• Have any contraindications for magnetic resonance imaging (MRI), including claustrophobia or the presence of contraindicated metal (ferromagnetic) implants/cardiac pacemaker.
• Have a screening MRI that shows evidence of significant abnormality.
• Have history of suicidal behavior, or a lifetime history of suicide attempt or acute suicidality.
• Have a history of
• Severe or ongoing allergy or hypersensitivity reactions
• Hypersensitivity to immunizations or immunoglobulins
• Two or more clinically significant or severe drug allergies,
• Intolerance to topical corticosteroids or severe posttreatment hypersensitivity reactions
• Have current serious or unstable illnesses, including hepatic, renal, gastroenterological, respiratory, cardiovascular, neurologic (other than AD), psychiatric, endocrinologic, immunologic, hematologic disease, or other conditions
• Require treatment with another monoclonal antibody or have received treatment with biologic agents (such as monoclonal antibodies, including marketed drugs) within 3 months or 5 half-lives (whichever is longer) prior to dosing.
• Have criteria that would preclude a lumbar puncture (LP).
• Are currently enrolled in a clinical study involving an investigational product (IP) or any other type of medical research judged not to be scientifically or medically compatible with this study.
• Have a current exposure to amyloid-targeting therapies (ATTs). Prior exposure to ATTs greater than 1 year from the last dose may be permitted at the discretion of the investigator and in consultation with the sponsor.

Sponsors & Collaborators

• Eli Lilly and Company: lead

Study Sites (7)

Flinders Medical Centre

Adelaide, 5042, Australia

Location

University of the Sunshine Coast Clinical Trial Centre

Birtinya, 4575, Australia

Location

Austin Health - Heidelberg Repatriation Hospital

Ivanhoe, 3079, Australia

Location

Southern Neurology

Kogarah, 2217, Australia

Location

Macquarie University Hospital

Macquarie University, 2109, Australia

Location

The Alfred

Melbourne, 3004, Australia

Location

Lilly Centre for Clinical Pharmacology

Singapore, 138623, Singapore

Location

MeSH Terms

Conditions

Alzheimer Disease; Cognitive Dysfunction; Neurodegenerative Diseases; Dementia

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Tauopathies; Neurocognitive Disorders; Mental Disorders; Cognition Disorders

Study Officials

• Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 8 AM - 8 PM Eastern time (UTC/GMT - 5 hours, EST)

  Eli Lilly and Company

  STUDY DIRECTOR

Central Study Contacts

Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or

CONTACT

1-317-615-4559; LillyTrials@Lilly.com

Physicians interested in becoming principal investigators please contact

CONTACT

clinical_inquiry_hub@lilly.com

Study Design

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

Study Record Dates

• First Submitted: May 14, 2026
• First Posted: May 20, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027
• Last Updated: May 20, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

SG (1); AU (6)