Trial Outcomes & Findings for Study of MK-6552 in Participants With Narcolepsy Type 1 (MK-6552-004) (NCT NCT06179407)

Last Updated: 2026-04-14

Results Overview

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.

Recruitment status

TERMINATED

Study phase

PHASE1

Target enrollment

9 participants

Primary outcome timeframe

1 hour after Dose 1 and Dose 2 on Day 7

Results posted on

2026-04-14

Participant Flow

Adult participants with narcolepsy type 1 were enrolled at 5 study sites in the United States.

Participant milestones

Participant milestones
Measure	Panel A Participants received a single dose (0.1, 0.25, 0.5 and 1 mg) of MK-6552 twice on a single day, with each dose separated by ≥4 days of washout. Participants then received MK-6552 1 mg (1 participant received MK-6552 0.1 mg) or placebo for 7 days in a counter-balanced order. Two days of washout separated the repeated treatments, and there were 14 days of follow-up post-treatment.	Panel B Panel B was not initiated due to early study termination.
Single Doses (Days 1 to 16) STARTED	9	0
Single Doses (Days 1 to 16) Period 1: MK-6552 0.1 mg + 4-Day Washout	9	0
Single Doses (Days 1 to 16) Period 2: MK-6552 0.25 mg + 4-Day Washout	8	0
Single Doses (Days 1 to 16) Period 3: MK-6552 0.5 mg + 4-Day Washout	7	0
Single Doses (Days 1 to 16) Period 4: MK-6552 1 mg + 4-Day Washout	8	0
Single Doses (Days 1 to 16) COMPLETED	8	0
Single Doses (Days 1 to 16) NOT COMPLETED	1	0
Single Dose Washout (Days 17 to 20) STARTED	8	0
Single Dose Washout (Days 17 to 20) COMPLETED	7	0
Single Dose Washout (Days 17 to 20) NOT COMPLETED	1	0
Repeated Treatment 1 (Days 21 to 29) STARTED	7	0
Repeated Treatment 1 (Days 21 to 29) MK-6552 1.0 mg x 7 Days + 2-Day Washout	5	0
Repeated Treatment 1 (Days 21 to 29) Placebo x 7 Days + 2-Day Washout	3	0
Repeated Treatment 1 (Days 21 to 29) COMPLETED	6	0
Repeated Treatment 1 (Days 21 to 29) NOT COMPLETED	1	0
Repeated Treatment 2 (Days 30 to 51) STARTED	6	0
Repeated Treatment 2 (Days 30 to 51) MK-6552 1.0 mg x 7 Days + 2-Day Washout	1	0
Repeated Treatment 2 (Days 30 to 51) MK-6552 0.1 mg x 7 Days + 2-Day Washout	1	0
Repeated Treatment 2 (Days 30 to 51) Placebo x 7 Days + 2-Day Washout	4	0
Repeated Treatment 2 (Days 30 to 51) COMPLETED	6	0
Repeated Treatment 2 (Days 30 to 51) NOT COMPLETED	0	0

Reasons for withdrawal

Reasons for withdrawal
Measure	Panel A Participants received a single dose (0.1, 0.25, 0.5 and 1 mg) of MK-6552 twice on a single day, with each dose separated by ≥4 days of washout. Participants then received MK-6552 1 mg (1 participant received MK-6552 0.1 mg) or placebo for 7 days in a counter-balanced order. Two days of washout separated the repeated treatments, and there were 14 days of follow-up post-treatment.	Panel B Panel B was not initiated due to early study termination.
Single Doses (Days 1 to 16) Withdrawal by Subject	1	0
Single Dose Washout (Days 17 to 20) Withdrawal by Subject	1	0
Repeated Treatment 1 (Days 21 to 29) Withdrawal by Subject	1	0

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Panel A n=9 Participants Participants received a single dose (0.1, 0.25, 0.5 and 1 mg) of MK-6552 twice on a single day, with each dose separated by ≥4 days of washout. Participants then received MK-6552 1 mg (1 participant received MK-6552 0.1 mg) or placebo for 7 days in a counter-balanced order. Two days of washout separated the repeated treatments, and there were 14 days of follow-up post-treatment.
Age, Continuous	33.7 years STANDARD_DEVIATION 12.6 • n=193 Participants
Sex: Female, Male Female	6 Participants n=193 Participants
Sex: Female, Male Male	3 Participants n=193 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=193 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	7 Participants n=193 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=193 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=193 Participants
Race (NIH/OMB) Asian	1 Participants n=193 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=193 Participants
Race (NIH/OMB) Black or African American	3 Participants n=193 Participants
Race (NIH/OMB) White	5 Participants n=193 Participants
Race (NIH/OMB) More than one race	0 Participants n=193 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=193 Participants

PRIMARY outcome

Timeframe: Up to ~34 weeks

Population: All treated participants are included.

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.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=7 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days n=6 Participants Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days n=1 Participants Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days n=7 Participants Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=9 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Number of Participants Experiencing an Adverse Event (AE)	1 Participants	1 Participants	2 Participants	0 Participants	1 Participants	3 Participants	2 Participants

PRIMARY outcome

Timeframe: Up to ~34 weeks

Population: All treated participants are included.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=7 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days n=6 Participants Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days n=1 Participants Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days n=7 Participants Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=9 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Number of Participants Discontinuing Study Intervention Due to AE	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants	0 Participants

PRIMARY outcome

Timeframe: 1 hour after Dose 1 and Dose 2 on Day 7

Population: All treated participants who received 7 days treatment with either MK-6552 0.1 mg or 1 mg or placebo are included.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days n=6 Participants Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days n=1 Participants Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days n=7 Participants Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Sleep Onset Latency Measured by the Maintenance of Wakefulness Test (MWT) Following 7 Days of MK-6554 Treatment 1 Hour after Dose 1	—	—	18.63 minutes Interval 0.0 to 40.0	8.50 minutes NA due to n=1	10.30 minutes Interval 0.0 to 21.82	—	—
Sleep Onset Latency Measured by the Maintenance of Wakefulness Test (MWT) Following 7 Days of MK-6554 Treatment 1 Hour after Dose 2	—	—	29.80 minutes Interval 8.92 to 40.0	40.00 minutes NA due to n=1	12.19 minutes Interval 0.0 to 27.95	—	—

SECONDARY outcome

Timeframe: 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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The AUC0-∞ of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=5 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=6 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Area Under the Plasma Concentration-Time Curve of MK-6552 From Time Zero to Infinity (AUC0-∞)	51.8 hr*nmol/L Interval 40.2 to 66.7	106 hr*nmol/L Interval 80.1 to 139.0	—	—	—	7.99 hr*nmol/L Interval 6.22 to 10.3	26.2 hr*nmol/L Interval 20.1 to 34.1

SECONDARY outcome

Timeframe: 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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included..

The AUC0-24 of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=6 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Area Under the Plasma Concentration-Time Curve of MK-6552 From Time Zero to 24 Hours Postdose (AUC0-24)	41.1 hr*nmol/L Interval 33.4 to 50.6	78.7 hr*nmol/L Interval 63.4 to 97.7	—	—	—	7.22 hr*nmol/L Interval 5.93 to 8.79	19.8 hr*nmol/L Interval 16.2 to 24.2

SECONDARY outcome

Timeframe: 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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The Cmax of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=6 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Maximum Concentration (Cmax) of MK-6552 Day 1 Dose 1	5.96 nmol/L Interval 4.58 to 7.77	10.0 nmol/L Interval 7.59 to 13.3	—	—	—	1.35 nmol/L Interval 1.06 to 1.72	3.46 nmol/L Interval 2.69 to 4.45
Maximum Concentration (Cmax) of MK-6552 Day 1 Dose 2	3.84 nmol/L Interval 2.72 to 5.4	7.69 nmol/L Interval 5.13 to 11.5	—	—	—	0.500 nmol/L Interval 0.366 to 0.684	1.34 nmol/L Interval 0.969 to 1.85

SECONDARY outcome

Timeframe: 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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The Tmax of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=6 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Time to Maximum Concentration (Tmax) of MK-6552 Day 1 Dose 2	2.30 hours Interval 0.5 to 4.0	2.98 hours Interval 0.98 to 6.05	—	—	—	4.02 hours Interval 2.55 to 6.33	2.53 hours Interval 0.97 to 8.0
Time to Maximum Concentration (Tmax) of MK-6552 Day 1 Dose 1	1.00 hours Interval 0.5 to 1.47	1.03 hours Interval 0.53 to 2.0	—	—	—	0.52 hours Interval 0.48 to 2.23	0.79 hours Interval 0.5 to 1.32

SECONDARY outcome

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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The C2h of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=6 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Concentration of MK-6522 at 2 Hours Postdose (C2h) Day 1 Dose 1	3.31 nmol/L Interval 2.54 to 4.33	6.68 nmol/L Interval 5.07 to 8.8	—	—	—	0.559 nmol/L Interval 0.4333 to 0.722	1.66 nmol/L Interval 1.28 to 2.15
Concentration of MK-6522 at 2 Hours Postdose (C2h) Day 1 Dose 2	3.19 nmol/L Interval 2.2 to 4.61	5.35 nmol/L Interval 3.49 to 8.19	—	—	—	0.389 nmol/L Interval 0.277 to 0.546	0.997 nmol/L Interval 0.703 to 1.41

SECONDARY outcome

Timeframe: Day 1 Dose 1: 6 hours postdose

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The C6h of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=6 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Concentration of MK-6522 at 6 Hours Postdose (C6h)	0.861 nmol/L Interval 0.667 to 1.11	1.81 nmol/L Interval 1.39 to 2.35	—	—	—	0.171 nmol/L Interval 0.134 to 0.22	0.405 nmol/L Interval 0.315 to 0.52

SECONDARY outcome

Timeframe: Day 1 Dose 2: 18 hours postdose

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The C18h of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=5 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=4 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Concentration of MK-6522 at 18 Hours Postdose (C18h)	0.617 nmol/L Interval 0.422 to 0.904	1.19 nmol/L Interval 0.784 to 1.81	—	—	—	0.157 nmol/L Interval 0.101 to 0.244	0.323 nmol/L Interval 0.223 to 0.467

SECONDARY outcome

Timeframe: 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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The CL/F of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=5 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=6 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Apparent Oral Clearance (CL/F) of MK-6552	43.0 Liters/hour Geometric Coefficient of Variation 35.1	45.0 Liters/hour Geometric Coefficient of Variation 22.9	—	—	—	52.3 Liters/hour Geometric Coefficient of Variation 34.8	42.6 Liters/hour Geometric Coefficient of Variation 32.7

SECONDARY outcome

Timeframe: 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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The Vz/F of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=5 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=6 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Apparent Volume of Distribution (Vz/F) of MK-6552	608.9 Liters Geometric Coefficient of Variation 32.5	546.7 Liters Geometric Coefficient of Variation 17.1	—	—	—	376.4 Liters Geometric Coefficient of Variation 39.6	489.2 Liters Geometric Coefficient of Variation 21.5

SECONDARY outcome

Timeframe: 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

Population: All treated participants who received 2 oral doses spaced 6 hours apart and have data available are included.

The apparent t½ of MK-6554 was determined for arms receiving 2 oral doses spaced 6 hours apart.

Outcome measures

Outcome measures
Measure	MK-6552 0.5 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=5 Participants Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg n=7 Participants Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=6 Participants Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.
Apparent Terminal Half-life (t½) of MK-6552	9.8 hours Geometric Coefficient of Variation 21.9	8.4 hours Geometric Coefficient of Variation 24.7	—	—	—	5.0 hours Geometric Coefficient of Variation 71.8	8.0 hours Geometric Coefficient of Variation 40.5

Adverse Events

MK-6552 0.1 mg

Serious events: 0 serious events

Other events: 3 other events

Deaths: 3 deaths

MK-6552 0.25 mg

Serious events: 0 serious events

Other events: 2 other events

Deaths: 2 deaths

MK-6552 0.5 mg

Serious events: 0 serious events

Other events: 1 other events

Deaths: 1 deaths

MK-6552 1 mg

Serious events: 0 serious events

Other events: 1 other events

Deaths: 1 deaths

MK-6552 1 mg x 7 Days

Serious events: 0 serious events

Other events: 2 other events

Deaths: 2 deaths

MK-6552 0.1 mg x 7 Days

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Placebo x 7 Days

Serious events: 0 serious events

Other events: 1 other events

Deaths: 1 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	MK-6552 0.1 mg n=9 participants at risk Participants received 2 oral doses of MK-6552 0.1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.25 mg n=8 participants at risk Participants received 2 oral doses of MK-6552 0.25 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 0.5 mg n=7 participants at risk Participants received 2 oral doses of MK-6552 0.5 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg n=7 participants at risk Participants received 2 oral doses of MK-6552 1 mg spaced 6 hours apart, followed by ≥4 days of follow-up.	MK-6552 1 mg x 7 Days n=6 participants at risk Participants received oral doses of MK-6552 1 mg q8h for 7 days followed by ≥4 days of follow-up.	MK-6552 0.1 mg x 7 Days n=1 participants at risk Participants received oral doses of MK-6552 0.1 mg q8h for 7 days followed by ≥4 days of follow-up.	Placebo x 7 Days n=7 participants at risk Participants received oral doses of placebo q8h for 7 days followed by ≥4 days of follow-up.
Eye disorders Conjunctival hyperaemia	0.00% 0/9 • Up to ~34 weeks	0.00% 0/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	16.7% 1/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
Gastrointestinal disorders Nausea	0.00% 0/9 • Up to ~34 weeks	0.00% 0/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	14.3% 1/7 • Up to ~34 weeks	16.7% 1/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
General disorders Feeling abnormal	11.1% 1/9 • Up to ~34 weeks	0.00% 0/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
Musculoskeletal and connective tissue disorders Back pain	0.00% 0/9 • Up to ~34 weeks	0.00% 0/8 • Up to ~34 weeks	14.3% 1/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
Musculoskeletal and connective tissue disorders Neck pain	0.00% 0/9 • Up to ~34 weeks	0.00% 0/8 • Up to ~34 weeks	14.3% 1/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
Nervous system disorders Dizziness	11.1% 1/9 • Up to ~34 weeks	12.5% 1/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	14.3% 1/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
Nervous system disorders Headache	0.00% 0/9 • Up to ~34 weeks	12.5% 1/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	14.3% 1/7 • Up to ~34 weeks
Nervous system disorders Migraine	0.00% 0/9 • Up to ~34 weeks	0.00% 0/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	16.7% 1/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	14.3% 1/7 • Up to ~34 weeks
Psychiatric disorders Insomnia	11.1% 1/9 • Up to ~34 weeks	12.5% 1/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
Renal and urinary disorders Pollakiuria	11.1% 1/9 • Up to ~34 weeks	0.00% 0/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks
Vascular disorders Orthostatic hypotension	11.1% 1/9 • Up to ~34 weeks	12.5% 1/8 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks	0.00% 0/6 • Up to ~34 weeks	0.00% 0/1 • Up to ~34 weeks	0.00% 0/7 • Up to ~34 weeks

Additional Information

Senior Vice President, Global Clinical Development

Merck Sharp & Dohme LLC

Phone: 1-800-672-6372

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee If publication activity is not directed by the Sponsor, the investigator agrees to submit all manuscripts or abstracts to the Sponsor before submission.
Publication restrictions are in place

Restriction type: OTHER