RecruitingPhase 1

A Study of LY3439539 in Participants With Alzheimer's Disease

A Phase 1, Open Label, Multiple-Dose Study to Assess the Changes in Cerebrospinal Fluid Biomarkers for Alzheimer's Disease Following Treatment With LY3439539 in Participants With Symptomatic Alzheimer's Disease

Lead sponsor

Eli Lilly and Company

Asset

LY3439539

Listed sites

Recruiting sites

Enrollment

estimated

Study population

Alzheimer’s disease

Key I/E criteria

•Alzheimer's disease•MRI contraindications excluded

Primary endpoint

•Neurofilament light (NfL)

Footprint

Where this trial recruits

Site locations as reported to ClinicalTrials.gov. Site count is not enrollment count; per-site enrollment is not available from source.

Identifiers

Registered as

Org study ID18818

Secondary IDI9M-MC-ONAAEli Lilly and Company

NCT IDNCT07598370

Timeline

Milestones

Study first posted2026-05-20actual

Study start2026-05-21actual

Last update posted2026-06-16actual

Primary completion2027-05estimated (month precision)

Study completion2027-05estimated (month precision)

Assets

Drug assets

LY3439539

Study populations

Who this study enrolls

Alzheimer’s disease

Eligibility

Who can enroll

Minimum age50 Years

Maximum age85 Years

SexAll

Healthy volunteersNot accepted

Inclusion criteria

•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)

Exclusion criteria

•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.

Endpoints (5)

What's being measured

Protocol endpoints and posted registry outcome measures, grouped into outcome categories. Composite endpoints show their component event types. Standard codes (LOINC, SNOMED CT) are shown where available.

Coverage by outcome category

Neurodegeneration biomarkers

Tau biomarkers

Safety / tolerability / PK

Other (unclassified)

Tau biomarkers

1 endpoint

Secondary/protocol endpoint

Change from Baseline in Phospho-Tau (pTau)

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

change from baseline, improvement

Neurodegeneration biomarkers

2 endpoints

Primary/protocol endpoint

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

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

Neurofilament light (NfL)

change from baseline, improvement

Secondary/protocol endpoint

Change from Baseline in Plasma NfL

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

Neurofilament light (NfL)

change from baseline, improvement

Safety / tolerability / PK

1 endpoint

Secondary/protocol endpoint

Pharmacokinetics (PK) Maximum LY3439539 Serum Concentration (Cmax)

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

concentration, descriptive

Other (unclassified)

1 endpoint

Secondary/protocol endpoint/low confidence

PK: Minimum LY3439539 Serum Concentration (Cmin)

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

concentration, descriptive

Provenance

Sources

Trial identity, design, statusClinicalTrials.gov API v2

Snapshot dateJuly 21, 2026

Endpoint classificationDelfa ADRD endpoint taxonomy

Results tableno registry results posted yet

Trial facts come from public ClinicalTrials.gov records. Endpoint categories are Delfa's classification of those records, not a ClinicalTrials.gov field. All figures reflect the July 21, 2026 snapshot.