Study of MK-6552 in Participants With Narcolepsy Type 1 (MK-6552-004)

NCT06179407 | Terminated Phase 1 Results FDA Drug

• 2 other identifiers: 6552-004MK-6554-004
• Study Type: interventional
• Target: 9
• Locations: 1 country
• Sites: 5

Brief Summary

The purpose of this study was to evaluate the safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of MK-6552 in participants with Narcolepsy Type 1 (NT1). The effect of single MK-6552 doses were assessed initially under open-label conditions to evaluate the safety, tolerability, and PK of MK-6552. The effect of repeated MK-6552 doses (every 8 hours \[q8h\] for 7 days) were assessed under double-blind and placebo-controlled conditions.

Conditions

Narcolepsy

Outcome Measures

Primary Outcomes (3)

• Number of Participants Experiencing an Adverse Event (AE)

  An AE is any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Events are reported according to dose. The number of participants with ≥1 AE is reported.

  Up to ~34 weeks

• Number of Participants Discontinuing Study Intervention Due to AE

  An AE is any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Events are reported according to dose. The number of participants that discontinued study intervention due to AE(s) is reported.

  Up to ~34 weeks

• Sleep Onset Latency Measured by the Maintenance of Wakefulness Test (MWT) Following 7 Days of MK-6554 Treatment

  The MWT is a daytime polysomnographic procedure that measures objectively the ability to remain awake during sleep-inducing circumstances. Sleep onset latency is defined as the first occurrence of sustained sleep (i.e. 3 consecutive 30 second epochs of N1 \[stage 1\] sleep or any single 30 second epoch of N2 \[stage 2\], N3 \[stage 3 and 4 combined\] or REM). The primary outcome measure of sleep onset latency measured by the MWT on Day 7 of daily repeated MK-6552 treatment is reported.

  1 hour after Dose 1 and Dose 2 on Day 7

Secondary Outcomes (10)

• Area Under the Plasma Concentration-Time Curve of MK-6552 From Time Zero to Infinity (AUC0-∞)

  Day 1 Dose 1: Predose, 0.25, 0.5, 1, 2, 3, 4, and 6 hours postdose 1. Day 1 Dose 2: 0.25, 0.5, 1, 2, 3, 4, 6, 8, 18, 21 and 24 hours postdose

• Area Under the Plasma Concentration-Time Curve of MK-6552 From Time Zero to 24 Hours Postdose (AUC0-24)

  Day 1 Dose 1: Predose, 0.25, 0.5, 1, 2, 3, 4, and 6 hours postdose 1. Day 1 Dose 2: 0.25, 0.5, 1, 2, 3, 4, 6, 8, and 18 hours postdose

• Maximum Concentration (Cmax) of MK-6552

  Day 1 Dose 1: Predose, 0.25, 0.5, 1, 2, 3, 4, and 6 hours postdose. Day 1 Dose 2: 0.25, 0.5, 1, 2, 3, 4, 6, 8, 18, 21 and 24 hours postdose

• Time to Maximum Concentration (Tmax) of MK-6552

  Day 1 Dose 1: Predose, 0.25, 0.5, 1, 2, 3, 4, and 6 hours postdose. Day 1 Dose 2: 0.25, 0.5, 1, 2, 3, 4, 6, 8, 18, 21 and 24 hours postdose

• Concentration of MK-6522 at 2 Hours Postdose (C2h)

  Day 1 Dose 1: 2 hours postdose. Day 1 Dose 2: 2 hours postdose.

Study Arms (2)

Panel A

EXPERIMENTAL

Participants will receive single oral doses of MK-6552 in ascending fashion approximately 6 hours apart for a single day, based on safety and tolerability of the previous dose. Then, participants will receive multiple days of MK-6552 dosing (7 consecutive days) at the highest safe and well tolerated MK-6552 dose determined on an individual basis from Part 1.

Drug: MK-6552; Drug: Placebo

Panel B

EXPERIMENTAL

Panel B will assess the effects of repeated MK-6552 dosing across a range of doses compared with placebo.

Drug: MK-6552; Drug: Placebo

Interventions

MK-6552 DRUG

Oral capsule

Panel A; Panel B

Placebo DRUG

Oral capsule matched to MK-6552

Panel A; Panel B

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Has a diagnosis of NT1, including a valid polysomnography within the previous 5 years and a current diagnosis of NT1 for at least 6 months based on criteria established by the International Classification of Sleep Disorders- Third Edition, or Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) \[American Psychiatric Association 2013\]
• Is positive for HLA-DQB1\*06:02 allele supporting a diagnosis of NT1
• Has a baseline history of unequivocal cataplexy prior to initiation of anti-cataplexy medications
• Reports a total sleep time of \> 6 hours on at least 4 out of 7 nights each week within the 4 weeks prior to screening visit

You may not qualify if:

• Has history of or current hypertension
• Has underlying cardiovascular or cerebrovascular conditions in which an acute rise in blood pressure would pose a clinical concern, including but nor limited to aneurysms or arteriovenous malformations
• Has a history of renal or hepatic impairment
• Has a history of cardiac ischemia or cerebral ischemia including but not limited to history of stroke, transient ischemic attack, or transient global amnesia
• Based on clinical interview and responses on the Columbia-Suicide Severity Rating Scale, is at imminent risk of self-harm or of harm to others in the opinion of the investigator
• Mentally or legally incapacitated, has significant emotional problems at the time of prestudy (screening) visit or expected during the conduct of the study or has a history of clinically significant psychiatric disorder of the last 5 years
• History of cancer (malignancy)
• Has a history of any of the following sleep disorders: obstructive sleep apnea (OSA) defined as an Apnea Hypopnea Index \> 15 per hour per the American Academy of Sleep Medicine alternate criteria, primary insomnia (within the past 6 months), circadian rhythm sleep disorder, shift work sleep disorder (within the past 6 months), clinically significant parasomnia at the discretion of the investigator
• Has a history of seizure disorder, clinically significant head trauma, or past invasive intracranial surgery or clinically significant dementia
• Positive test(s) for Hepatitis B surface antigen, hepatitis C antibodies, or human immunodeficiency virus

Sponsors & Collaborators

• Merck Sharp & Dohme LLC: lead

Study Sites (5)

Delta Waves, Inc. ( Site 0008)

Colorado Springs, Colorado, 80918, United States

Location

Teradan Clinical Trials, LLC ( Site 0005)

Brandon, Florida, 33511, United States

Location

NeuroTrials Research Inc ( Site 0006)

Atlanta, Georgia, 30328, United States

Location

Bogan Sleep Consultants ( Site 0001)

Columbia, South Carolina, 29201, United States

Location

FutureSearch Trials of Neurology ( Site 0004)

Austin, Texas, 78731, United States

Location

Related Links

• Merck Clinical Trials Information

MeSH Terms

Conditions

Narcolepsy

Condition Hierarchy (Ancestors)

Disorders of Excessive Somnolence; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Mental Disorders

Results Point of Contact

• Title: Senior Vice President, Global Clinical Development
• Organization: Merck Sharp & Dohme LLC

ClinicalTrialsDisclosure@msd.com

1-800-672-6372

Study Officials

• Medical Director

  Merck Sharp & Dohme LLC

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 12, 2023
• First Posted: December 21, 2023
• Study Start: January 24, 2024
• Primary Completion: October 23, 2024
• Study Completion: October 23, 2024
• Last Updated: April 14, 2026
• Results First Posted: April 14, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will share

Locations

US (5)