TerminatedPhase 2Results posted

Efficacy and Safety of MK-1942 as an Adjunct Therapy in Participants With Mild to Moderate Alzheimer's Disease Dementia (MK-1942-008)

A Phase 2a/2b Randomized, Placebo-Controlled Clinical Study To Evaluate The Safety And Efficacy Of MK-1942 As Adjunctive Therapy In Participants With Mild To Moderate Alzheimer's Disease Dementia

Lead sponsor

Merck Sharp & Dohme LLC

Asset

MK-1942

Listed sites

Recruiting sites

Enrollment

actual

Study population

Alzheimer’s disease

Key I/E criteria

•mild-to-moderate AD / moderate AD dementia•MMSE 12-22•Study partner/caregiver required

Primary endpoints

•ADAS-Cog•Adverse Event (AE)•Number of Participants Discontinuing Study Medication Due to an Adverse Event

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 ID1942-008

Eudract number2021-006336-94

RegistryjRCT2031220532jRCT

Secondary IDMK-1942-008MSD Protocol Number

NCT IDNCT05602727

Timeline

Milestones

Study first posted2022-11-02actual

Study start2022-12-02actual

Primary completion2023-09-27actual

Study completion2023-09-27actual

Results first posted2024-10-15actual

Last update posted2024-12-10actual

Assets

Drug assets

MK-1942

Study populations

Who this study enrolls

Alzheimer’s disease

Eligibility

Who can enroll

Minimum age55 Years

Maximum age90 Years

SexAll

Healthy volunteersNot accepted

Inclusion criteria

•Has mild to moderate AD dementia based on the national institute of neurological and communicative diseases and stroke/Alzheimer's Disease and related disorders association (NINCDS-ADRDA) criteria.

•Has mini-mental state examination (MMSE) score between 12-22 (inclusive) at screening.

•Is using acetylcholinesterase inhibitors (AChEI) therapy for management of AD dementia at Screening and during the study. These medications must be at stable approved dose levels ≥3 months before the first dose of study intervention and the regimens must remain constant throughout the study to the extent that is clinically appropriate.

•Has a designated study partner who can fulfill the requirements of this study. The study partner will need to spend sufficient time with the participant to be familiar with their overall function and behavior and be able to provide adequate information about the participant needed for the study including, knowledge of functional and basic activities of daily life, work/educational history, cognitive performance, emotional/psychological state, and general health status

Exclusion criteria

•Has a known history of stroke or cerebrovascular disease that is clinically important in the investigator's opinion.

•Has diagnosis of a clinically relevant central nervous system (CNS) disease other than AD dementia (with protocol-specified exceptions).

•Has a history of seizures or epilepsy within the 10 years preceding Screening.

•Has any other major CNS trauma, or infections that affect brain function.

•Has evidence of a clinically relevant or unstable psychiatric disorder, based on criteria from the diagnostic and statistical manual of mental disorders (fifth edition), including schizophrenia or other psychotic disorder, bipolar disorder, major depression, or delirium. Major depression in remission is not exclusionary.

•Has a severe, acute, or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or administration intervention.

•Has a history of malignancy occurring within the 5 years immediately before Screening, except for a participant who has been adequately treated for 1 or more of the following: basal cell or squamous cell skin cancer; in situ cervical cancer; localized prostate carcinoma; who has undergone potentially curative therapy with no evidence of recurrence for ≥3 years post-therapy, and who is deemed to be at low risk for recurrence.

•Has a risk factor for QTc prolongation.

•Has a history of alcoholism or drug dependency/abuse within the 5 years preceding screening.

•Has a known allergy or intolerance to the active or inert ingredients in MK-1942.

•Has received any anti-amyloid agents or antibodies, or any of the following medications: CNS-penetrant anticholinergics, neuroleptics, anticonvulsants, narcotics, glutamatergic agents, agents with possible psychotropic effects, and experimental acute respiratory syndrome coronavirus 2 (COVID-19) therapies.

•Has liver disease, including but not limited to chronic viral hepatitis, non viral hepatitis, cirrhosis, malignancies, autoimmune liver diseases.

•Has an abnormal thyroid-stimulating hormone (TSH) value if confirmed by abnormal T4 value.

•Resides in a nursing home or assisted care facility with need for direct continuous medical care and nursing supervision. Participant may reside in such facilities provided continuous direct medical care is not required and a qualified study partner is available for coparticipation and the participant is physically able to attend all required study visits.

•Had major surgical procedure or donated or lost >1 unit of blood (approximately 500 mL) within the 4 weeks before screening.

Endpoints (10)

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

Global cognition

Function / daily living

Other clinical outcomes

Global cognition

2 endpoints

Primary/protocol endpoint

Change From Baseline in the Alzheimer's Disease Assessment Scale-11-item Cognitive Subscale (ADAS-Cog11) Score at Week 12

Time frame:Baseline and Week 12

ADAS-Cog

change from baseline, improvement

Primary/registry result

Change From Baseline in the Alzheimer's Disease Assessment Scale-11-item Cognitive Subscale (ADAS-Cog11) Score at Week 12

Time frame:Baseline and Week 12

ADAS-Cog

change from baseline, improvement

Posted result

Group	Value (least_squares_mean), Units on a scale	Reported bounds
MK-1942 5 mgn=20 Participants	2.9	-0.7 - 5.1
MK-1942 15 mgn=21 Participants	-0.6	--3.0 - 1.8
Placebon=25 Participants	0.8	--1.4 - 3.0

LS Mean Difference2.197.5% CI-1.6 - 5.8p0.186Longitudinal ANCOVA

LS Mean Difference-1.497.5% CI-5.2 - 2.4p0.400Longitudinal ANCOVA

Function / daily living

2 endpoints

Secondary/protocol endpoint

Mean Change From Baseline in The Alzheimer's Disease Cooperative Study Activities of Daily Living (ADCS-ADL) Total Score at Week 12

Time frame:Baseline and Week 12

ADCS-Activities of Daily Living (ADCS-ADL)

change from baseline, improvement

Secondary/registry result

Mean Change From Baseline in The Alzheimer's Disease Cooperative Study Activities of Daily Living (ADCS-ADL) Total Score at Week 12

Time frame:Baseline and Week 12

ADCS-Activities of Daily Living (ADCS-ADL)

change from baseline, improvement

Posted result

Group	Value (least_squares_mean), Units on a scale	Reported bounds
MK-1942 5 mgn=20 Participants	-1.7	--4.8 - 1.4
MK-1942 15 mgn=21 Participants	-3.0	--6.4 - 0.4
Placebon=25 Participants	1.2	--2.0 - 4.4

LS Mean Difference-2.997.5% CI-8.0 - 2.2p0.196Longitudinal ANCOVA

LS Mean Difference-4.297.5% CI-9.6 - 1.3p0.081Longitudinal ANCOVA

Safety / tolerability / PK

4 endpoints

Primary/protocol endpoint

Number of Participants Experiencing an Adverse Event (AE)

Time frame:Up to ~ 14 Weeks

event count, event

Primary/protocol endpoint

Number of Participants Discontinuing Study Medication Due to an Adverse Event

Time frame:Up to ~ 12 Weeks

event count, event

Primary/registry result

Number of Participants Experiencing an Adverse Event (AE)

Time frame:Up to ~ 14 Weeks

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
MK-1942 5 mgn=34 Participants	17	-
MK-1942 15 mgn=31 Participants	21	-
Placebon=33 Participants	18	-

Primary/registry result

Number of Participants Discontinuing Study Medication Due to an Adverse Event

Time frame:Up to ~ 12 Weeks

event count, event

Posted result

Group	Value (count_of_participants), Participants	Reported bounds
MK-1942 5 mgn=34 Participants	4	-
MK-1942 15 mgn=31 Participants	6	-
Placebon=33 Participants	3	-

Other clinical outcomes

2 endpoints

Secondary/protocol endpoint

Alzheimer's Disease Cooperative Study Clinical Global Impression of Change (ADCS-CGIC) Overall Score at Week 12

Time frame:Week 12

change from baseline, improvement

Secondary/registry result

Alzheimer's Disease Cooperative Study Clinical Global Impression of Change (ADCS-CGIC) Overall Score at Week 12

Time frame:Week 12

change from baseline, improvement

Posted result

Group	Value (mean), Units on a scale	Standard deviation
MK-1942 5 mgn=14 Participants	5.4	0.7
MK-1942 15 mgn=11 Participants	5.8	0.9
Placebon=13 Participants	5.3	0.8

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.