Dose Finding Study in Adults With Attention-Deficit/Hyperactivity Disorder (ADHD)(174007/P05805/MK-8777-003)

A Double Blind, Placebo Controlled, Randomized, Two Period 4-Arm Trial to Investigate the Dose-Related Efficacy and Safety of Org 26576 in Adults With Attention-Deficit/Hyperactivity Disorder (ADHD)

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00610441

Enrollment

Registered

2008-02-08

Start date

2008-04-01

Completion date

2009-03-09

Last updated

2018-10-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Attention Deficit Hyperactivity Disorder

Keywords

randomized, double blind, placebo controlled

Brief summary

This is a Phase 2 multicenter, randomized, double-blind trial of MK-8777 (Org 26576, SCH 900777) in adult subjects with Attention-Deficit/Hyperactivity Disorder (ADHD). MK-8777 or placebo will be administered in a crossover fashion for two 3-week treatment periods. The two 3-week treatment periods will be separated by a 2-week placebo washout period. The primary objective is to compare the efficacy of various doses of MK-8777 to that of placebo in the treatment of ADHD symptoms in adults.

Interventions

DRUGMK-8777

DRUGPlacebo

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

ALL

Age

18 Years to 50 Years

Healthy volunteers

Inclusion criteria

* are between 18-50 years, inclusive; * are male; or female who are non-pregnant, non-lactating and using an acceptable method of birth control (intrauterine device, double-barrier method, hormonal contraceptives); or female of non-childbearing potential if they are a) surgically sterile (tubal ligation, hysterectomy and/or bilateral oophorectomy) and provide documentation of the procedure by operative report or ultrasound scan, or b) post-menopausal for greater than one year with follicle stimulating hormone (FSH) level greater than or equal to 40 mIU/mL at screening. All females must have a negative serum pregnancy test at screening; * are outpatients; * provide written informed consent * are fluent in the language of the investigator, * are able to discontinue the use of any psychotropic medications for the treatment of ADHD symptoms at screening; * meet strict operational criteria for adult ADHD according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV-TRTM) * have a Clinical Global Impression ADHD score of 4 or higher at screening

Exclusion criteria

* have any clinically significant concurrent medical condition (endocrine, renal, respiratory, cardiovascular, hematological, immunological, cerebrovascular, neurological, anorexia, obesity or malignancy) that has become unstable and may interfere with the interpretation of safety and efficacy evaluations. * have any clinically significant abnormal laboratory, vital sign, physical examination, or electrocardiogram (ECG) findings at screening that, in the opinion of the investigator, may interfere with the interpretation of safety or efficacy evaluations. * have any history of liver disease (e.g., cirrhosis, hepatitis), or liver injury;(history of hepatitis A greater than one year prior to screening is acceptable); any abnormal clinically significant findings at screening on liver laboratory parameters (serum glutamic-pyruvic transaminase \[SGPT\], serum glutamic oxaloacetic transaminase \[SGOT\], gamma-glutamyltransferase \[GGT\], lactate dehydrogenase \[LDH\], bilirubin, albumin, protein, alkaline phosphatase); * have a seizure disorder beyond childhood or are taking any anticonvulsants to prevent seizures; * have known serological evidence of human immunodeficiency virus (HIV) antibody; * have a positive test result at screening on hepatitis B surface antigen or hepatitis A immunoglobulin M (IgM) antibodies or hepatitis C total antibodies; * are pregnant as confirmed by a positive serum pregnancy test at screening; * have QTc values \>450 msec at screening using Fridericia's QTc formula; * have a confirmed positive result in the alcohol/drug screen test for alcohol, illegal or non-prescribed drugs at screening (except marijuana/ tetrahydrocannabinol \[THC\]); * have a confirmed positive result in the alcohol/drug screen re-test for marijuana/THC; * have current or lifetime history of bipolar and psychotic disorders; * have a current major depression disorder, obsessive-compulsive disorder, post-traumatic stress disorder, generalized anxiety disorder, panic disorder and eating disorder (also if treated but not currently symptomatic); * have a current comorbid dysthymia or social anxiety disorder that is currently treated with psychotropic medication; * have a current untreated social anxiety disorder that may interfere with the assessment of ADHD in the investigator's opinion; * present an imminent risk of self-harm or harm to others; * have any history of a significant suicide attempt, or possess a current risk of attempting suicide, in the investigator's opinion, based on clinical interview and responses provided on the Beck Scale for Suicidal Ideation (BSS); * have a history of jailing or imprisonment in the past 6 months due to worsening of symptoms of ADHD;

Design outcomes

Primary

Measure	Time frame	Description
Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Baseline (BL) and Day 7, Day 14, Day 21	The AISRS is an 18-item clinician-rated instrument for assessing the 18 core symptoms of ADHD corresponding to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) diagnostic symptoms for adults. Based on the clinician's rating for each of the symptoms using a 4-point scale (0=None to 3=Severe), the AISRS total score is derived by summing the score assigned to each of the 18 symptoms. Scores can range from 0 to 54, with a higher score indicating a more severe ADHD symptoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2. For the statistical analyses, the average score from Day 14 and Day 21 was used.

Secondary

Measure	Time frame	Description
Percentage of Participants With at Least a 50% Reduction From Baseline in AISRS Score	Baseline and Day 21	The AISRS is an 18-item clinician-rated instrument for assessing the 18 core symptoms of ADHD corresponding to the DSM-IV diagnostic symptoms for adults. Based on the clinician's rating for each of the symptoms using a 4-point scale (0=None to 3=Severe), the AISRS total score is derived by summing the score assigned to each of the 18 symptoms. Scores can range from 0 to 54, with a higher score indicating a more severe ADHD symptoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2. Reduction was defined as the relative change from the baseline score within a treatment period to post-baseline score within that treatment period.
Percentage of Participants Who Experience At Least One Adverse Event (AE)	Up to 7 days after last dose of study drug (Up to 63 days)	An AE is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of an investigational product, whether or not related to the investigational product. AEs are reported by study drug taken at time of event and not by randomly assigned sequence.
Percentage of Participants Who Discontinue Study Drug Due to an AE	Up to last dose of study drug (Up to 56 days)	An AE is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of an investigational product, whether or not related to the investigational product. AEs are reported by study drug taken at time of event and not by randomly assigned sequence.
Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Days 14-21	The CGI-S is a 7-point clinician-rated scale for assessing the global severity of ADHD. Scores could range from 1=Normal, not at all ill to 7=Among the most extremely ill, with a higher score indicating more severe illness. Categorization was as follows: 1=Normal, not at all ill and Borderline mentally ill; 2=Mildly ill; 3=Moderately ill and 4=Markedly ill, Severely ill and Among the most extremely ill patients, with a higher category indicating more severe illness. Analysis of CGI-S was performed using a proportional odds model. For statistical analyses, CGI-S assessments were condensed to one assessment of severity per treatment period by taking the most severe score at the second and third visits within a treatment period.
Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Days 14-21	The CGI-I is a 7-point clinician-rated scale for assessing the global improvement of ADHD. Scores could range from 1=Very much improved to 4=No change to 7=Very much worse, with a lower score indicating the most improvement. Analysis of CGI-I was performed using a proportional odds model. For statistical analyses, CGI-I assessments were condensed to one assessment of improvement per treatment period by taking the worst improvement score at the second and third visits within a treatment period.
Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Baseline and Day 7, Day 14, Day 21	The ESS is an 8-item scale used to assess sleepiness. The test consists of a list of 8 situations in which participants rate their tendency to become sleepy on a scale of 0=Would never doze to 3=High chance of dozing. The scores for each of the 8 situations are added to create a total score on a scale with a range from of 0 to 24. A higher score indicates a greater degree of sleepiness. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.
Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Baseline and Day 7, Day 14, Day 21	The PSQI is a participant-rated scale to assess the quality of sleep. The PSQI consists of 7 component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each component score can range from 0=better (i.e., 0 times per month) to 3=worse (i.e., 3 or more times per week). The sum of these 7 component scores yields one total score with a range of 0 (better) to 21 (worse). A total PSQI score \<=5 is associated with good sleep quality; a total score \>5 is associated with poor sleep quality. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.
Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Baseline and Day 7, Day 14, Day 21	The QIDS-C is a clinician-administered rating scale to measure the severity of depressive symptoms within the 9 DSM-IV major depression disorder symptom (MDD) domains: depressed mood, loss of interest or pleasure, concentration/decision making, self-outlook, suicidal ideation, energy/fatigability, sleep, weight/appetite change, and psychomotor changes. There is one score (0=none to 3=severe) for each of the of the 9 domains. The total score is obtained by adding the scores for each of the 9 symptom domains. QIDS-C total scores can range from 0 to 27, with a higher score indicating more severe depression. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.
Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Baseline and Day 7, Day 14, Day 21	The TASS is a participant-administered scale to assess study drug effects in the evening. Participants respond to 18 questions about ADHD symptoms, with scores from 0=Not at all to 3=Severe. Total scores can range from 0 to 54, with a higher score indicating more severe ADHD symtoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.
Computerized Cognition Assessment: Cognitive Flexibility	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing (©CNS Vital Signs, Chapel Hill, NC) battery consisting of neuropsychological tests that measure the cognitive domain of cognitive flexibility (score range: -200 to 200), with a higher score indicating better cognition.
Percentage of Participants With at Least a 30% Reduction From Baseline in AISRS Score	Baseline and Day 21	The AISRS is an 18-item clinician-rated instrument for assessing the 18 core symptoms of ADHD corresponding to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) diagnostic symptoms for adults. Based on the clinician's rating for each of the symptoms using a 4-point scale (0=None to 3=Severe), the AISRS total score is derived by summing the score assigned to each of the 18 symptoms. Scores can range from 0 to 54, with a higher score indicating a more severe ADHD symptoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2. Reduction was defined as the relative change from the baseline score within a treatment period to post-baseline score within that treatment period.
Computerized Cognition Assessment: Composite Memory	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of composite memory (score range: -120 to 120), with a higher score indicating better cognition.
Computerized Cognition Assessment: Executive Functioning	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of executive functioning (score range: -200 to 200), with a higher score indicating better cognition.
Computerized Cognition Assessment: Speed of Processing	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of speed of processing (score range: -1000 to 200), with a higher score indicating better cognition.
Computerized Cognition Assessment: Reaction Time	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of reaction time (lowest time possible is 0 msec), with a lower reaction time indicating better cognition.
Computerized Cognition Assessment: Reasoning	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of reasoning (score range: -15 to 15), with a higher score indicating better cognition.
Computerized Cognition Assessment: Sustained Attention	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of sustained attention (score range -120 to 120), with a higher score indicating better cognition.
Computerized Cognition Assessment: Verbal Memory	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of verbal memory (score range: -60 to 60), with a higher score indicating better cognition.
Computerized Cognition Assessment: Visual Memory	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of visual memory (score range: -60 to 60), with a higher score indicating better cognition.
Computerized Cognition Assessment: Working Memory	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of working memory (score range: -48 to 48), with a higher score indicating better cognition.
Computerized Cognition Assessment: Complex Attention	Baseline, Day 21	Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of complex attention (score range: 0 to 250), with a lower score indicating better cognition.

Participant flow

Participants by arm

Arm	Count
MK-8777 FD→PBO Participants receive a fixed dose FD of MK-8777 100 mg BID for 3 weeks (Treatment Period 1). After a 2-week placebo washout period, participants receive a fixed dose of placebo BID for 3 weeks (Treatment Period 2).	15
PBO→MK-8777 FD Participants receive a fixed dose of placebo BID for 3 weeks (Treatment Period 1). After a 2-week placebo washout period, participants receive a fixed dose of MK-8777 100 mg BID for 3 weeks (Treatment Period 2).	16
MK-8777 RD→PBO Participants receive rising doses of MK-8777 100-300 mg BID for 3 weeks (Treatment Period 1). After a 2-week placebo washout period, participants receive rising doses of placebo BID for 3 weeks (Treatment Period 2).	18
PBO→MK-8777 RD Participants receive rising doses of placebo BID for 3 weeks (Treatment Period 1). After a 2-week placebo washout period, participants receive rising doses of MK-8777 100-300 mg BID for 3 weeks (Treatment Period 2).	18
Total	67

Withdrawals & dropouts

Period	Reason	FG000	FG001	FG002	FG003
Placebo Washout Period - 2 Weeks	Adverse Event	0	0	2	0
Placebo Washout Period - 2 Weeks	Withdrawal by Subject	0	1	0	0
Treatment Period 1 - 3 Weeks	Adverse Event	1	1	4	1
Treatment Period 1 - 3 Weeks	Lack of Efficacy	0	0	1	0
Treatment Period 1 - 3 Weeks	Lost to Follow-up	1	1	1	0
Treatment Period 1 - 3 Weeks	Withdrawal by Subject	1	0	1	1
Treatment Period 2 - 3 Weeks	Adverse Event	0	0	0	1
Treatment Period 2 - 3 Weeks	Lack of Efficacy	1	0	0	0
Treatment Period 2 - 3 Weeks	Other	1	1	0	1

Baseline characteristics

Characteristic	MK-8777 FD→PBO	PBO→MK-8777 FD	MK-8777 RD→PBO	PBO→MK-8777 RD	Total
Age, Continuous	34.9 years STANDARD_DEVIATION 8.7	35.1 years STANDARD_DEVIATION 9.2	36.7 years STANDARD_DEVIATION 8.8	40.7 years STANDARD_DEVIATION 6.3	37.0 years STANDARD_DEVIATION 8.4
Sex: Female, Male Female	3 Participants	5 Participants	9 Participants	5 Participants	22 Participants
Sex: Female, Male Male	12 Participants	11 Participants	9 Participants	13 Participants	45 Participants

Adverse events

Event type	EG000 affected / at risk	EG001 affected / at risk	EG002 affected / at risk
deaths Total, all-cause mortality	— / —	— / —	— / —
other Total, other adverse events	23 / 55	14 / 28	26 / 34
serious Total, serious adverse events	1 / 55	0 / 28	0 / 34

Outcome results

Primary

Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score

The AISRS is an 18-item clinician-rated instrument for assessing the 18 core symptoms of ADHD corresponding to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) diagnostic symptoms for adults. Based on the clinician's rating for each of the symptoms using a 4-point scale (0=None to 3=Severe), the AISRS total score is derived by summing the score assigned to each of the 18 symptoms. Scores can range from 0 to 54, with a higher score indicating a more severe ADHD symptoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2. For the statistical analyses, the average score from Day 14 and Day 21 was used.

Time frame: Baseline (BL) and Day 7, Day 14, Day 21

Population: The Intent-to-Treat (ITT) population consisted of all participants who were randomized, who received at least one dose of study drug in at least one period, and who had at least one postbaseline AISRS efficacy assessment. Results are reported by the study drug being administered at time of assessment and not by randomly assigned sequence.

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	0.0 score on a scale	Standard Deviation 6.7
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-1.0 score on a scale	Standard Deviation 8.9
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-1.4 score on a scale	Standard Deviation 9.4
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	-3.7 score on a scale	Standard Deviation 7.1
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-7.5 score on a scale	Standard Deviation 10.8
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-7.3 score on a scale	Standard Deviation 8.6
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-5.1 score on a scale	Standard Deviation 7.4
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	-3.4 score on a scale	Standard Deviation 6.5
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-6.8 score on a scale	Standard Deviation 9.1
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	-3.9 score on a scale	Standard Deviation 7.6
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-3.3 score on a scale	Standard Deviation 9.4
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-4.6 score on a scale	Standard Deviation 7.7

Comparison: The treatment difference between 100 mg MK-8777 fixed dose and Placebo was estimated for the average effect (average change from baseline) of the 2nd and 3rd week of each period (Day 14 and Day 21).p-value: 0.014797.5% CI: [-10.911, -0.4881]Mixed Model for Repeated Measurements

Comparison: The treatment difference between 100-300 mg MK-8777 rising dose and Placebo was estimated for the average effect (average change from baseline) of the 2nd and 3rd week of each period (Day 14 and Day 21).p-value: 0.59197.5% CI: [-3.2961, 5.2814]MMRM

Secondary

Change From Baseline in Epworth Sleepiness Scale (ESS) Score

The ESS is an 8-item scale used to assess sleepiness. The test consists of a list of 8 situations in which participants rate their tendency to become sleepy on a scale of 0=Would never doze to 3=High chance of dozing. The scores for each of the 8 situations are added to create a total score on a scale with a range from of 0 to 24. A higher score indicates a greater degree of sleepiness. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.

Time frame: Baseline and Day 7, Day 14, Day 21

Population: The ITT population consisted of all participants who were randomized, who received at least one dose of study drug in at least one period, and who had at least one postbaseline ESS efficacy assessment.

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 7 (n=25, 25, 27, 30)	-0.6 score on a scale	Standard Deviation 4
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-0.9 score on a scale	Standard Deviation 4
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-1.6 score on a scale	Standard Deviation 3.8
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 7 (n=25, 25, 27, 30)	-1.1 score on a scale	Standard Deviation 2.5
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-0.8 score on a scale	Standard Deviation 3.8
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-1.7 score on a scale	Standard Deviation 2.3
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-1.3 score on a scale	Standard Deviation 3.7
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 7 (n=25, 25, 27, 30)	-0.7 score on a scale	Standard Deviation 3.1
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-0.7 score on a scale	Standard Deviation 4.6
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 7 (n=25, 25, 27, 30)	1.5 score on a scale	Standard Deviation 5.4
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	1.1 score on a scale	Standard Deviation 3.1
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Epworth Sleepiness Scale (ESS) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	1.2 score on a scale	Standard Deviation 4.7

Secondary

Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score

The PSQI is a participant-rated scale to assess the quality of sleep. The PSQI consists of 7 component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each component score can range from 0=better (i.e., 0 times per month) to 3=worse (i.e., 3 or more times per week). The sum of these 7 component scores yields one total score with a range of 0 (better) to 21 (worse). A total PSQI score \<=5 is associated with good sleep quality; a total score \>5 is associated with poor sleep quality. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.

Time frame: Baseline and Day 7, Day 14, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 7 (N=25, 26, 27, 30)	-0.7 score on a scale	Standard Deviation 1.7
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 21 (n=21, 25, 24, 23)	-1.1 score on a scale	Standard Deviation 2.5
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 14 (N=25, 27, 27, 27)	-0.5 score on a scale	Standard Deviation 1.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 7 (N=25, 26, 27, 30)	-0.6 score on a scale	Standard Deviation 2
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 21 (n=21, 25, 24, 23)	-0.7 score on a scale	Standard Deviation 2.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 14 (N=25, 27, 27, 27)	-0.1 score on a scale	Standard Deviation 3.6
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 14 (N=25, 27, 27, 27)	-0.8 score on a scale	Standard Deviation 2.3
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 7 (N=25, 26, 27, 30)	0.6 score on a scale	Standard Deviation 3.2
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 21 (n=21, 25, 24, 23)	-0.4 score on a scale	Standard Deviation 2.1
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 7 (N=25, 26, 27, 30)	-0.4 score on a scale	Standard Deviation 2.2
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 21 (n=21, 25, 24, 23)	-0.3 score on a scale	Standard Deviation 2.6
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score	Change from BL at Day 14 (N=25, 27, 27, 27)	-0.1 score on a scale	Standard Deviation 2.4

Secondary

Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score

The QIDS-C is a clinician-administered rating scale to measure the severity of depressive symptoms within the 9 DSM-IV major depression disorder symptom (MDD) domains: depressed mood, loss of interest or pleasure, concentration/decision making, self-outlook, suicidal ideation, energy/fatigability, sleep, weight/appetite change, and psychomotor changes. There is one score (0=none to 3=severe) for each of the of the 9 domains. The total score is obtained by adding the scores for each of the 9 symptom domains. QIDS-C total scores can range from 0 to 27, with a higher score indicating more severe depression. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.

Time frame: Baseline and Day 7, Day 14, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	0.2 score on a scale	Standard Deviation 1.7
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	0.1 score on a scale	Standard Deviation 2.6
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	0.3 score on a scale	Standard Deviation 2.9
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	-0.1 score on a scale	Standard Deviation 2.3
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	0.5 score on a scale	Standard Deviation 2.1
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	0.0 score on a scale	Standard Deviation 2.9
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	-0.3 score on a scale	Standard Deviation 1.4
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	-0.1 score on a scale	Standard Deviation 2.2
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	-0.5 score on a scale	Standard Deviation 1.9
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 7 (n=25, 26, 27, 30)	-0.3 score on a scale	Standard Deviation 2.5
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 21 (n=22, 25, 24, 23)	0.1 score on a scale	Standard Deviation 2.7
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score	Change from BL at Day 14 (n=25, 27, 27, 27)	0.3 score on a scale	Standard Deviation 2.5

Secondary

Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score

The TASS is a participant-administered scale to assess study drug effects in the evening. Participants respond to 18 questions about ADHD symptoms, with scores from 0=Not at all to 3=Severe. Total scores can range from 0 to 54, with a higher score indicating more severe ADHD symtoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2.

Time frame: Baseline and Day 7, Day 14, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 7 (n=20, 23, 22, 25)	0.3 score on a scale	Standard Deviation 6.5
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 21 (n=15, 23, 21, 19)	-2.2 score on a scale	Standard Deviation 7.3
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 14 (n=20, 22, 20, 25)	-0.4 score on a scale	Standard Deviation 8.1
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 7 (n=20, 23, 22, 25)	-1.1 score on a scale	Standard Deviation 6.5
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 21 (n=15, 23, 21, 19)	-3.0 score on a scale	Standard Deviation 8.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 14 (n=20, 22, 20, 25)	-2.2 score on a scale	Standard Deviation 7.8
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 14 (n=20, 22, 20, 25)	-2.4 score on a scale	Standard Deviation 6.2
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 7 (n=20, 23, 22, 25)	0.0 score on a scale	Standard Deviation 6.2
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 21 (n=15, 23, 21, 19)	-2.9 score on a scale	Standard Deviation 8.4
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 7 (n=20, 23, 22, 25)	-1.5 score on a scale	Standard Deviation 4.7
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 21 (n=15, 23, 21, 19)	-1.3 score on a scale	Standard Deviation 6.9
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score	Change from BL at Day 14 (n=20, 22, 20, 25)	-1.7 score on a scale	Standard Deviation 6.5

Secondary

Computerized Cognition Assessment: Cognitive Flexibility

Cognition was assessed by a computerized cognitive testing (©CNS Vital Signs, Chapel Hill, NC) battery consisting of neuropsychological tests that measure the cognitive domain of cognitive flexibility (score range: -200 to 200), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Cognitive Flexibility	BL (n=27, 27, 26, 32)	48.0 score on a scale	Standard Deviation 18.1
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Cognitive Flexibility	Day 21 (n=21, 25, 25, 23)	50.3 score on a scale	Standard Deviation 14.1
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Cognitive Flexibility	Day 21 (n=21, 25, 25, 23)	49.2 score on a scale	Standard Deviation 20.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Cognitive Flexibility	BL (n=27, 27, 26, 32)	49.5 score on a scale	Standard Deviation 17.9
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Cognitive Flexibility	BL (n=27, 27, 26, 32)	47.1 score on a scale	Standard Deviation 19.5
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Cognitive Flexibility	Day 21 (n=21, 25, 25, 23)	50.9 score on a scale	Standard Deviation 14.8
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Cognitive Flexibility	BL (n=27, 27, 26, 32)	46.5 score on a scale	Standard Deviation 20.5
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Cognitive Flexibility	Day 21 (n=21, 25, 25, 23)	50.7 score on a scale	Standard Deviation 16.5

Secondary

Computerized Cognition Assessment: Complex Attention

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of complex attention (score range: 0 to 250), with a lower score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Complex Attention	BL (n=27, 27, 26, 32)	11.9 score on a scale	Standard Deviation 22
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Complex Attention	Day 21 (n=21, 25, 25, 23)	18.1 score on a scale	Standard Deviation 39
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Complex Attention	Day 21 (n=21, 25, 25, 23)	12.8 score on a scale	Standard Deviation 14.4
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Complex Attention	BL (n=27, 27, 26, 32)	17.3 score on a scale	Standard Deviation 32
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Complex Attention	BL (n=27, 27, 26, 32)	13.5 score on a scale	Standard Deviation 26.1
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Complex Attention	Day 21 (n=21, 25, 25, 23)	9.6 score on a scale	Standard Deviation 15.5
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Complex Attention	BL (n=27, 27, 26, 32)	10.8 score on a scale	Standard Deviation 15.9
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Complex Attention	Day 21 (n=21, 25, 25, 23)	16.0 score on a scale	Standard Deviation 31.3

Secondary

Computerized Cognition Assessment: Composite Memory

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of composite memory (score range: -120 to 120), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Composite Memory	BL (n=27, 27, 26, 32)	92.5 score on a scale	Standard Deviation 8.7
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Composite Memory	Day 21 (n=21, 25, 25, 23)	98.8 score on a scale	Standard Deviation 10.2
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Composite Memory	Day 21 (n=21, 25, 25, 23)	93.1 score on a scale	Standard Deviation 9.5
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Composite Memory	BL (n=27, 27, 26, 32)	92.6 score on a scale	Standard Deviation 10.5
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Composite Memory	BL (n=27, 27, 26, 32)	96.9 score on a scale	Standard Deviation 9.7
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Composite Memory	Day 21 (n=21, 25, 25, 23)	96.0 score on a scale	Standard Deviation 11.8
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Composite Memory	BL (n=27, 27, 26, 32)	96.7 score on a scale	Standard Deviation 9.4
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Composite Memory	Day 21 (n=21, 25, 25, 23)	96.0 score on a scale	Standard Deviation 12.4

Secondary

Computerized Cognition Assessment: Executive Functioning

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of executive functioning (score range: -200 to 200), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Executive Functioning	BL (n=27, 27, 26, 32)	49.8 score on a scale	Standard Deviation 17.1
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Executive Functioning	Day 21 (n=21, 25, 25, 23)	52.0 score on a scale	Standard Deviation 13.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Executive Functioning	Day 21 (n=21, 25, 25, 23)	50.9 score on a scale	Standard Deviation 19.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Executive Functioning	BL (n=27, 27, 26, 32)	50.9 score on a scale	Standard Deviation 17.7
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Executive Functioning	BL (n=27, 27, 26, 32)	49.3 score on a scale	Standard Deviation 19.5
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Executive Functioning	Day 21 (n=21, 25, 25, 23)	53.1 score on a scale	Standard Deviation 14
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Executive Functioning	BL (n=27, 27, 26, 32)	48.1 score on a scale	Standard Deviation 20.3
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Executive Functioning	Day 21 (n=21, 25, 25, 23)	52.5 score on a scale	Standard Deviation 15.6

Secondary

Computerized Cognition Assessment: Reaction Time

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of reaction time (lowest time possible is 0 msec), with a lower reaction time indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reaction Time	BL (n=27, 27, 26, 32)	646.7 msec	Standard Deviation 87.3
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reaction Time	Day 21 (n=21, 25, 25, 23)	634.4 msec	Standard Deviation 74.6
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reaction Time	Day 21 (n=21, 25, 25, 23)	621.7 msec	Standard Deviation 152
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reaction Time	BL (n=27, 27, 26, 32)	645.6 msec	Standard Deviation 81.6
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reaction Time	BL (n=27, 27, 26, 32)	653.1 msec	Standard Deviation 118.8
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reaction Time	Day 21 (n=21, 25, 25, 23)	646.7 msec	Standard Deviation 139.3
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reaction Time	BL (n=27, 27, 26, 32)	673.8 msec	Standard Deviation 124.1
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reaction Time	Day 21 (n=21, 25, 25, 23)	642.4 msec	Standard Deviation 111.5

Secondary

Computerized Cognition Assessment: Reasoning

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of reasoning (score range: -15 to 15), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reasoning	BL (n=27, 27, 26, 32)	6.6 score on a scale	Standard Deviation 4.6
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reasoning	Day 21 (n=21, 25, 25, 23)	7.9 score on a scale	Standard Deviation 3.3
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reasoning	Day 21 (n=21, 25, 25, 23)	8.2 score on a scale	Standard Deviation 3.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Reasoning	BL (n=27, 27, 26, 32)	7.7 score on a scale	Standard Deviation 4.6
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reasoning	BL (n=27, 27, 26, 32)	5.9 score on a scale	Standard Deviation 3.3
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reasoning	Day 21 (n=21, 25, 25, 23)	7.4 score on a scale	Standard Deviation 4.1
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reasoning	BL (n=27, 27, 26, 32)	7.5 score on a scale	Standard Deviation 3.3
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Reasoning	Day 21 (n=21, 25, 25, 23)	7.1 score on a scale	Standard Deviation 3.7

Secondary

Computerized Cognition Assessment: Speed of Processing

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of speed of processing (score range: -1000 to 200), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Speed of Processing	BL (n=27, 27, 26, 32)	63.8 score on a scale	Standard Deviation 16.1
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Speed of Processing	Day 21 (n=21, 25, 25, 23)	64.1 score on a scale	Standard Deviation 9.1
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Speed of Processing	Day 21 (n=21, 25, 25, 23)	63.5 score on a scale	Standard Deviation 15.5
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Speed of Processing	BL (n=27, 27, 26, 32)	64.3 score on a scale	Standard Deviation 15.8
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Speed of Processing	BL (n=27, 27, 26, 32)	58.0 score on a scale	Standard Deviation 10.6
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Speed of Processing	Day 21 (n=21, 25, 25, 23)	60.9 score on a scale	Standard Deviation 10.6
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Speed of Processing	BL (n=27, 27, 26, 32)	58.9 score on a scale	Standard Deviation 8
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Speed of Processing	Day 21 (n=21, 25, 25, 23)	59.9 score on a scale	Standard Deviation 9

Secondary

Computerized Cognition Assessment: Sustained Attention

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of sustained attention (score range -120 to 120), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Sustained Attention	BL (n=27, 27, 26, 32)	26.1 score on a scale	Standard Deviation 12
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Sustained Attention	Day 21 (n=21, 25, 25, 23)	29.5 score on a scale	Standard Deviation 5.6
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Sustained Attention	Day 21 (n=21, 25, 25, 23)	25.5 score on a scale	Standard Deviation 9.3
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Sustained Attention	BL (n=27, 27, 26, 32)	28.9 score on a scale	Standard Deviation 7.9
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Sustained Attention	BL (n=27, 27, 26, 32)	27.0 score on a scale	Standard Deviation 8.2
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Sustained Attention	Day 21 (n=21, 25, 25, 23)	29.7 score on a scale	Standard Deviation 7.6
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Sustained Attention	BL (n=27, 27, 26, 32)	28.4 score on a scale	Standard Deviation 8.9
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Sustained Attention	Day 21 (n=21, 25, 25, 23)	27.3 score on a scale	Standard Deviation 10.4

Secondary

Computerized Cognition Assessment: Verbal Memory

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of verbal memory (score range: -60 to 60), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Verbal Memory	BL (n=27, 27, 26, 32)	49.4 score on a scale	Standard Deviation 4.8
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Verbal Memory	Day 21 (n=21, 25, 25, 23)	52.4 score on a scale	Standard Deviation 5
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Verbal Memory	Day 21 (n=21, 25, 25, 23)	51.3 score on a scale	Standard Deviation 5.2
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Verbal Memory	BL (n=27, 27, 26, 32)	48.7 score on a scale	Standard Deviation 5.7
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Verbal Memory	BL (n=27, 27, 26, 32)	50.8 score on a scale	Standard Deviation 5.9
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Verbal Memory	Day 21 (n=21, 25, 25, 23)	51.2 score on a scale	Standard Deviation 6.1
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Verbal Memory	BL (n=27, 27, 26, 32)	51.5 score on a scale	Standard Deviation 4.9
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Verbal Memory	Day 21 (n=21, 25, 25, 23)	50.2 score on a scale	Standard Deviation 6.3

Secondary

Computerized Cognition Assessment: Visual Memory

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of visual memory (score range: -60 to 60), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Visual Memory	BL (n=27, 27, 26, 32)	43.0 score on a scale	Standard Deviation 6.4
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Visual Memory	Day 21 (n=21, 25, 25, 23)	46.3 score on a scale	Standard Deviation 6.8
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Visual Memory	Day 21 (n=21, 25, 25, 23)	41.8 score on a scale	Standard Deviation 6.7
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Visual Memory	BL (n=27, 27, 26, 32)	43.8 score on a scale	Standard Deviation 6.3
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Visual Memory	BL (n=27, 27, 26, 32)	46.2 score on a scale	Standard Deviation 5.8
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Visual Memory	Day 21 (n=21, 25, 25, 23)	44.8 score on a scale	Standard Deviation 7.6
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Visual Memory	BL (n=27, 27, 26, 32)	45.3 score on a scale	Standard Deviation 6
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Visual Memory	Day 21 (n=21, 25, 25, 23)	45.9 score on a scale	Standard Deviation 7.1

Secondary

Computerized Cognition Assessment: Working Memory

Cognition was assessed by a computerized cognitive testing battery consisting of neuropsychological tests that measure the cognitive domain of working memory (score range: -48 to 48), with a higher score indicating better cognition.

Time frame: Baseline, Day 21

Arm	Measure	Group	Value (MEAN)	Dispersion
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Working Memory	BL (n=27, 27, 26, 32)	9.8 score on a scale	Standard Deviation 6.3
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Working Memory	Day 21 (n=21, 25, 25, 23)	10.0 score on a scale	Standard Deviation 4.1
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Working Memory	Day 21 (n=21, 25, 25, 23)	8.5 score on a scale	Standard Deviation 5.2
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Computerized Cognition Assessment: Working Memory	BL (n=27, 27, 26, 32)	10.2 score on a scale	Standard Deviation 5
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Working Memory	BL (n=27, 27, 26, 32)	10.0 score on a scale	Standard Deviation 5.1
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Working Memory	Day 21 (n=21, 25, 25, 23)	10.3 score on a scale	Standard Deviation 5.1
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Working Memory	BL (n=27, 27, 26, 32)	9.6 score on a scale	Standard Deviation 4.9
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Computerized Cognition Assessment: Working Memory	Day 21 (n=21, 25, 25, 23)	8.9 score on a scale	Standard Deviation 6

Secondary

Percentage of Participants Who Discontinue Study Drug Due to an AE

An AE is defined as any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of an investigational product, whether or not related to the investigational product. AEs are reported by study drug taken at time of event and not by randomly assigned sequence.

Time frame: Up to last dose of study drug (Up to 56 days)

Population: The AST population consisted of all participants who received at least one dose of randomized study drug within at least one of the two treatment periods (excluding the placebo run-in period).

Arm	Measure	Value (NUMBER)
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants Who Discontinue Study Drug Due to an AE	3.6 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants Who Discontinue Study Drug Due to an AE	3.6 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants Who Discontinue Study Drug Due to an AE	20.6 percentage of participants

Secondary

Percentage of Participants Who Experience At Least One Adverse Event (AE)

Time frame: Up to 7 days after last dose of study drug (Up to 63 days)

Population: The All-Subjects-Treated (AST) population consisted of all participants who received at least one dose of randomized study drug within at least one of the two treatment periods (excluding the placebo run-in period).

Arm	Measure	Value (NUMBER)
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants Who Experience At Least One Adverse Event (AE)	56.4 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants Who Experience At Least One Adverse Event (AE)	71.4 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants Who Experience At Least One Adverse Event (AE)	85.3 percentage of participants

Secondary

Percentage of Participants With at Least a 30% Reduction From Baseline in AISRS Score

The AISRS is an 18-item clinician-rated instrument for assessing the 18 core symptoms of ADHD corresponding to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) diagnostic symptoms for adults. Based on the clinician's rating for each of the symptoms using a 4-point scale (0=None to 3=Severe), the AISRS total score is derived by summing the score assigned to each of the 18 symptoms. Scores can range from 0 to 54, with a higher score indicating a more severe ADHD symptoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2. Reduction was defined as the relative change from the baseline score within a treatment period to post-baseline score within that treatment period.

Time frame: Baseline and Day 21

Population: The ITT population consisted of all participants who were randomized, who received at least one dose of study drug, and who had at least one postbaseline AISRS efficacy assessment.

Arm	Measure	Value (NUMBER)
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With at Least a 30% Reduction From Baseline in AISRS Score	12.0 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With at Least a 30% Reduction From Baseline in AISRS Score	41.0 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With at Least a 30% Reduction From Baseline in AISRS Score	33.0 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With at Least a 30% Reduction From Baseline in AISRS Score	30.0 percentage of participants

95% CI: [1.799, 26.0878]

95% CI: [0.3119, 2.8701]

Secondary

Percentage of Participants With at Least a 50% Reduction From Baseline in AISRS Score

The AISRS is an 18-item clinician-rated instrument for assessing the 18 core symptoms of ADHD corresponding to the DSM-IV diagnostic symptoms for adults. Based on the clinician's rating for each of the symptoms using a 4-point scale (0=None to 3=Severe), the AISRS total score is derived by summing the score assigned to each of the 18 symptoms. Scores can range from 0 to 54, with a higher score indicating a more severe ADHD symptoms. Baseline was defined as the score at the baseline visit prior to starting dosing for Period 1 and as the last score in the 2-week placebo wash-out period for Period 2. Reduction was defined as the relative change from the baseline score within a treatment period to post-baseline score within that treatment period.

Time frame: Baseline and Day 21

Population: The ITT population consisted of all participants who were randomized, who received at least one dose of study drug, and who had at least one postbaseline AISRS efficacy assessment.

Arm	Measure	Value (NUMBER)
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With at Least a 50% Reduction From Baseline in AISRS Score	0.0 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With at Least a 50% Reduction From Baseline in AISRS Score	19.0 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With at Least a 50% Reduction From Baseline in AISRS Score	19.0 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With at Least a 50% Reduction From Baseline in AISRS Score	4.0 percentage of participants

95% CI: [0.6712, 58.1395]

95% CI: [0.0152, 1.388]

Secondary

Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores

The CGI-I is a 7-point clinician-rated scale for assessing the global improvement of ADHD. Scores could range from 1=Very much improved to 4=No change to 7=Very much worse, with a lower score indicating the most improvement. Analysis of CGI-I was performed using a proportional odds model. For statistical analyses, CGI-I assessments were condensed to one assessment of improvement per treatment period by taking the worst improvement score at the second and third visits within a treatment period.

Time frame: Days 14-21

Population: The ITT population consisted of all participants who were randomized, who received at least one dose of study drug, and who had at least one postbaseline CGI-I efficacy assessment.

Arm	Measure	Group	Value (NUMBER)
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 1	0.0 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 6	0.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 5	4.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 2	12.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 7	0.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 3	20.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 4	64.00 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 6	0.00 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 4	55.56 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 3	25.93 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 5	3.70 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 7	0.00 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 2	11.11 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 1	3.70 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 4	48.15 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 1	3.70 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 2	3.70 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 3	40.74 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 5	3.70 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 6	0.00 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 7	0.00 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 3	40.74 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 7	0.00 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 6	0.00 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 2	14.81 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 1	3.70 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 5	7.41 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores	Score of 4	33.33 percentage of participants

95% CI: [0.5402, 3.2008]

95% CI: [0.524, 3.7309]

Secondary

Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores

The CGI-S is a 7-point clinician-rated scale for assessing the global severity of ADHD. Scores could range from 1=Normal, not at all ill to 7=Among the most extremely ill, with a higher score indicating more severe illness. Categorization was as follows: 1=Normal, not at all ill and Borderline mentally ill; 2=Mildly ill; 3=Moderately ill and 4=Markedly ill, Severely ill and Among the most extremely ill patients, with a higher category indicating more severe illness. Analysis of CGI-S was performed using a proportional odds model. For statistical analyses, CGI-S assessments were condensed to one assessment of severity per treatment period by taking the most severe score at the second and third visits within a treatment period.

Time frame: Days 14-21

Population: The ITT population consisted of all participants who were randomized, who received at least one dose of study drug, and who had at least one postbaseline CGI-S efficacy assessment.

Arm	Measure	Group	Value (NUMBER)
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 1	4.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 2	20.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 3	36.00 percentage of participants
Placebo: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 4	40.00 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 2	14.81 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 3	55.56 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 4	25.93 percentage of participants
MK-8777 100mg: MK-8777 FD→PBO OR PBO→MK-8777 FD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 1	3.70 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 3	55.56 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 2	11.11 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 4	29.63 percentage of participants
Placebo: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 1	3.70 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 4	18.52 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 2	22.22 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 1	7.41 percentage of participants
MK-8777 100-300mg: MK-8777 RD→PBO OR PBO→MK-8777 RD	Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores	Category 3	51.85 percentage of participants

95% CI: [0.5654, 2.5785]

95% CI: [0.6951, 4.9494]

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026

Dose Finding Study in Adults With Attention-Deficit/Hyperactivity Disorder (ADHD)(174007/P05805/MK-8777-003)

Conditions

Keywords

Brief summary

Related papers

Interventions

Sponsors

Study design

Eligibility

Inclusion criteria

Exclusion criteria

Design outcomes

Primary

Secondary

Participant flow

Participants by arm

Withdrawals & dropouts

Baseline characteristics

Adverse events

Outcome results

Change From Baseline in Adult Attention-Deficit/Hyperactivity Disorder (ADHD) Investigator Symptom Rating Scale (AISRS) Score

Change From Baseline in Epworth Sleepiness Scale (ESS) Score

Change From Baseline in Pittsburgh Sleep Quality Index (PSQI) Score

Change From Baseline in Quick Inventory of Depression Symptomology - Clinician Rating (QIDS-C) Score

Change From Baseline in Time-Sensitive ADHD Symptom Scale (TASS) Score

Computerized Cognition Assessment: Cognitive Flexibility

Computerized Cognition Assessment: Complex Attention

Computerized Cognition Assessment: Composite Memory

Computerized Cognition Assessment: Executive Functioning

Computerized Cognition Assessment: Reaction Time

Computerized Cognition Assessment: Reasoning

Computerized Cognition Assessment: Speed of Processing

Computerized Cognition Assessment: Sustained Attention

Computerized Cognition Assessment: Verbal Memory

Computerized Cognition Assessment: Visual Memory

Computerized Cognition Assessment: Working Memory

Percentage of Participants Who Discontinue Study Drug Due to an AE

Percentage of Participants Who Experience At Least One Adverse Event (AE)

Percentage of Participants With at Least a 30% Reduction From Baseline in AISRS Score

Percentage of Participants With at Least a 50% Reduction From Baseline in AISRS Score

Percentage of Participants With Clinician Global Impression Scale - Improvement (CGI-I) Scores

Percentage of Participants With Clinician Global Impression Scale - Severity (CGI-S) Category Scores