CompletedPhase 1Results posted

Elpipodect (MK-8189) Safety and Tolerability in Participants With Alzheimer's Disease With or Without Symptoms of Agitation-Aggression and/or Psychosis (MK-8189-017)

A Randomized Clinical Study to Evaluate the Safety and Tolerability of MK-8189 in Participants With Alzheimer's Disease With or Without Symptoms of Agitation-Aggression and/or Psychosis

Lead sponsor

Merck Sharp & Dohme LLC

Asset

Elpipodect

Listed sites

Recruiting sites

Enrollment

actual

Study population

Alzheimer’s disease

Key I/E criteria

•Alzheimer's disease•Study partner/caregiver required

Primary endpoints

•Adverse Event (AE)•Number of Participants Discontinuing From Study Therapy Due to AE

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 ID8189-017

Secondary IDMK-8189-017Merck

NCT IDNCT05227118

Timeline

Milestones

Study first posted2022-02-07actual

Study start2022-07-01actual

Primary completion2023-01-10actual

Study completion2023-01-10actual

Results first posted2024-09-25actual

Last update posted2026-04-29actual

Assets

Drug assets

Elpipodect

Study populations

Who this study enrolls

Alzheimer’s disease

Eligibility

Who can enroll

Minimum age65 Years

Maximum age85 Years

SexAll

Healthy volunteersNot accepted

Inclusion criteria

The main inclusion and exclusion criteria include but are not limited to the following:

Inclusion Criteria:

•Has a documented diagnosis of probable Alzheimer Disease based on National Institute on Aging-Alzheimer Association criteria for AD, with a history of cognitive and functional decline with gradual onset and slow progression for at least 1 year before screening, that is either corroborated by an informant who knows the participant well or is documented in medical records

•Lives in the community setting with a reliable trial partner/caregiver or lives alone in an assisted living facility, with supervision and has a reliable trial partner/caregiver

•Has a reliable and competent trial partner/caregiver who must have a close relationship with the participant and is knowledgeable of the participant's condition and progress and able to read, understand and speak the designated language at the study site

•Can read at the 6th grade level/equivalent as determined by the investigator

•Has an academic and/or employment history sufficient to exclude intellectual disability and is able, in the opinion of the investigator, to fully participate in the study

•Participants receiving treatment with a cholinesterase inhibitor or other treatment for AD, must have been on a stable regimen for 3 months prior to screening and there are no expected changes in co-medication during the study

•Is able to discontinue any antipsychotic medication they are taking at the time of Screening

•Has a body mass index (BMI) > 18 and ≤ 35kg/m2, inclusive

Exclusion criteria

•Has agitation/aggression or psychosis that is attributable to concomitant medications, environmental conditions, substance abuse, or an active medical or psychiatric condition

•Has a known history of stroke or evidence from prior magnetic resonance imaging (MRI) scan (if available) that is clinically important in the investigator's opinion

•Has evidence of a clinically relevant neurological disorder other than the disease being studied (i.e., probable AD) at Screening

•Has a history of seizures or epilepsy within the last 5 years before Screening

•Has evidence of a clinically relevant or unstable psychiatric disorder

•Is at imminent risk of self-harm

•Has a history of alcoholism or drug dependency/abuse within the last 5 years before Screening

•Has a history of cancer (malignancy). Exceptions: (1) Adequately treated non-melanomatous skin carcinoma or carcinoma in situ of the cervix or; (2) Other malignancies that have been successfully treated with appropriate follow up and therefore unlikely to recur for the duration of the study

•Has a family history of long QT syndrome

•Previously developed severe extrapyramidal symptoms (EPS) following administration of any prescribed medication or study treatment

•Is positive for hepatitis B surface antigen (HBsAg), hepatitis C antibodies or human immunodeficiency virus (HIV)

•Had major surgery, donated or lost 1 unit of blood (approximately 500 mL) within 4 weeks prior to the pre-study (screening) visit

•Consumes greater than 3 glasses of alcoholic beverages per day

•Consumes excessive amounts, defined as greater than 6 servings (1 serving is approximately equivalent to 120 mg of caffeine) of coffee, tea, cola, energy drinks, or other caffeinated beverages per day

•Is a regular user of cannabis, any illicit drugs or has a history of drug (including alcohol) abuse within approximately 3 years

Endpoints (4)

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

Safety / tolerability / PK

Other (unclassified)

Safety / tolerability / PK

2 endpoints

Primary/protocol endpoint

Number of Participants Who Experienced an Adverse Event (AE)

Time frame:Up to approximately 42 days

event count, event

Primary/registry result

Number of Participants Who Experienced an Adverse Event (AE)

Time frame:Up to approximately 42 days

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
MK-8189 8 mgn=22 Participants	3	-
MK-8189 16 mgn=22 Participants	8	-
MK-8189 24 mgn=14 Participants	5	-
Placebon=7 Participants	1	-

Other (unclassified)

2 endpoints

Primary/protocol endpoint/low confidence

Number of Participants Discontinuing From Study Therapy Due to AE

Time frame:Up to approximately 42 days

event count, event

Primary/registry result/low confidence

Number of Participants Discontinuing From Study Therapy Due to AE

Time frame:Up to approximately 42 days

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
MK-8189 8 mgn=22 Participants	1	-
MK-8189 16 mgn=22 Participants	0	-
MK-8189 24 mgn=14 Participants	0	-
Placebon=7 Participants	0	-

Provenance

Sources

Trial identity, design, statusClinicalTrials.gov API v2

Snapshot dateJuly 21, 2026

Endpoint classificationDelfa ADRD endpoint taxonomy

Results tableClinicalTrials.gov results section

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.