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Dose-optimization in Adolescents Aged 13-17 Diagnosed With Attention-deficit/Hyperactivity Disorder (ADHD) Using Extended-release Guanfacine HCl

A Phase 3, Double-blind, Randomized, Multi-center, Placebo Controlled, Dose-optimization Study Evaluating the Safety, Efficacy, and Tolerability of Once Daily Dosing With Extended-release Guanfacine Hydrochloride in Adolescents Aged 13-17 Years Diagnosed With Attention-deficit/Hyperactivity Disorder (ADHD)

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01081132
Enrollment
314
Registered
2010-03-05
Start date
2011-09-19
Completion date
2013-05-16
Last updated
2021-06-28

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

Conditions

Attention-Deficit/Hyperactivity Disorder

Brief summary

To assess the efficacy of optimized Extended-release Guanfacine Hydrochloride compared with placebo in the treatment of adolescents aged 13-17 years with a diagnosis of ADHD as measured by the ADHD-RS-IV

Interventions

The test product will be provided as 1, 2, 3, and 4mg tablets. Subjects will be administered a once-daily dose between 1-7mg/day depending on weight.

OTHERPlacebo

Matching placebo will be provided as 1,2,3, and 4mg tablets. Subjects will be administered a once-daily dose of placebo between 1-7mg/day depending on weight.

Sponsors

Shire
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
13 Years to 17 Years
Healthy volunteers
No

Inclusion criteria

1. Male or female, aged 13-17 years at the time of consent/assent (screening only). 2. Subject's parent or legally authorized representative (LAR) must provide signature of informed consent, and there must be documentation of assent by the subject indicating that the subject is aware of the investigational nature of the study and the required procedures and restrictions in accordance with the International Conference on Harmonisation (ICH) Good Clinical Practice (GCP) Guidance E6 (1996) and applicable regulations before completing any study-related procedures at screening. 3. Subject meets Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-Text Revision (DSM-IV-TR) criteria for a primary diagnosis of ADHD, combined subtype, or hyperactive/impulsive subtype, based on a detailed psychiatric evaluation using the Kiddie Schedule for Affective Disorders and Schizophrenia - Present and Lifetime version (K SADS PL) at screening (re-confirm if baseline visit is \>35 days from screening). 4. Subject has a minimum ADHD-RS-IV total score of 32 at baseline. 5. Subject has a minimum CGI-S score of 4 at baseline. 6. Subject is functioning at an age-appropriate level intellectually, as deemed by the Investigator. 7. Subject and parent/LAR understand, are able, willing and likely to fully comply with the study procedures and restrictions defined in this protocol. 8. Subject is able to swallow intact tablets. 9. All females must have a negative serum beta human Chorionic Gonadotropin (hCG) pregnancy test at screening and a negative urine pregnancy test at baseline. Female subjects must abstain from sexual activity that could result in pregnancy or agree to use acceptable methods of contraception. 10. Subject has a supine and standing blood pressure (BP) measurement within the 95th percentile for age, gender, and height.

Exclusion criteria

1. Subject has a current, controlled (requiring a prohibited medication or behavioral modification program) or uncontrolled, comorbid psychiatric diagnosis \[except Oppositional Defiant Disorder (ODD), but including all anxiety disorders (except simple phobias)\], all major depressive disorders (dysthymia allowed unless medication required), and any severe comorbid Axis II disorders or severe Axis I disorders such as post traumatic stress disorder, bipolar illness, psychosis, pervasive developmental disorder, obsessive-compulsive disorder, substance abuse disorder, or other symptomatic manifestations that, in the opinion of the Investigator, contraindicate SPD503 treatment or confound efficacy or safety assessments. 2. Subject has any condition or illness including clinically significant abnormal screening laboratory values which, in the opinion of the Investigator, represents an inappropriate risk to the subject and/or could confound the interpretation of the study. 3. Subject has a known history or presence of structural cardiac abnormalities, serious heart rhythm abnormalities, syncope, cardiac conduction problems (e.g., clinically significant heart block), exercise-related cardiac events including syncope and pre-syncope, or clinically significant bradycardia. 4. Subject has any abnormal or clinically significant ECG findings as judged by the Investigator with consideration of the central ECG interpretation. 5. Subject with orthostatic hypotension or a known history of controlled or uncontrolled hypertension. 6. Current use of any prohibited medication, including herbal supplements that affect blood pressure, heart rate, have central nervous system (CNS) effects, or affect cognitive performance, such as sedating antihistamines and decongestant sympathomimetics (inhaled bronchodilators are permitted) or a history of chronic use of sedating medications (i.e., antihistamines) at baseline. 7. Subject has a history of alcohol or other substance abuse or dependence, as defined by DSM IV-TR (with the exceptions of nicotine) within the last six months. 8. Subject has taken another investigational product within 30 days prior to baseline. 9. Subject is significantly overweight based on Center for Disease Control and Prevention Body Mass Index (BMI)-for-age gender specific charts at screening. Significantly overweight is defined as a BMI \>95th percentile for this study. 10. Body weight of less than 34.0kg or greater than 91.0kg at screening. 11. Subject has a known or suspected allergy, hypersensitivity, or clinically significant intolerance to guanfacine hydrochloride or any components found in SPD503. 12. Clinically important abnormality on urine drug and/or alcohol screen (excluding the subject's current ADHD stimulant if applicable). 13. Subject is female and is pregnant or currently lactating. 14. Subject failed screening or was previously enrolled in this study. 15. Subject who is currently considered a suicide risk, has previously made a suicide attempt, or has a prior history of, or is currently demonstrating suicidal ideation. 16. History of failure to respond to an adequate trial (consisting of an appropriate dose and adequate duration of therapy), in the opinion of the Investigator, of an α2-agonist for the treatment of ADHD. 17. Subject has a history of a seizure disorder (other than a single childhood febrile seizure occurring before the age of 3 years) or a history of a tic disorder (including Tourette's syndrome).

Design outcomes

Primary

MeasureTime frameDescription
Change From Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 13Baseline through week 13The ADHD-RS-IV consists of 18 items scored on a 4-point scale ranging from 0 (no symptoms) to 3 (severe symptoms) with total score ranging from 0 to 54.

Secondary

MeasureTime frameDescription
Change From Baseline in the WFIRS-P Social Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Social Domain consists of 7-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Percent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale at the Last On-Treatment AssessmentBaseline through week 13CGI-S assesses the severity of the subject's condition on a 7-point scale: 1 (normal, not at all ill), 2 (borderline mentally ill), 3 (mildly ill), 4 (moderately ill), 5 (markedly ill), 6 (severely ill), 7 (among the most extremely ill)
Change From Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Learning and School Domain Scores at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Learning and School Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Change From Baseline in the WFIRS-P Family Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Family Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Change From Baseline in the WFIRS-P Behavior in School Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Change From Baseline in the WFIRS-P Global Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Change From Baseline in the WFIRS-P Child Self-Concept Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Child Self-Concept Domain consists of 3-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Change From Baseline in the WFIRS-P Risk Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Risk Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Change From Baseline in the WFIRS-P Academic Performance Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.
Percent of Subjects With Improvement on Clinical Global Impression-Improvement (CGI-I) Scores at the Last On-Treatment Assessmentweeks 1 through 13Clinical Global Impression-Improvement (CGI-I) consists of a 7-point scale ranging from 1 (very much improved) to 7 (very much worse). Improvement is defined as a score of 1 (very much improved) or 2 (much improved) on the scale.
Changes From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13Baseline and week 13Behavior Rating Inventory of Executive Function (BRIEF) is a questionnaire composed of three indices: Global Executive Composite, Behavioral Regulation Index, and Metacognition Index. Items are rated 1 (never), 2 (sometimes), and 3 (often). The Global Executive Composite consists of 72 items with scoring ranging from 72 to 216. The Behavioral Regulation Index score is the total of 28 items and ranges from 28 to 84. The Metacognition Index score is the total of 44 items and ranges from 44 to 132. Lower scores reflect better functioning.
Change From Baseline in Pediatric Daytime Sleepiness Scale (PDSS) Total Score at Week 13Baseline through week 13The Pediatric Daytime Sleepiness Scale (PDSS) is an 8 item questionnaire scored on a scale from 0 (never) to 4 (always/very often). Total scores range from 0 to 32, with increasing score reflecting greater sleepiness.
Change From Baseline in Brief Psychiatric Rating Scale for Children (BPRS-C) Total Score at Last On-Treatment AssessmentBaseline and week 13The BPRS-C characterizes childhood behavioral and emotional symptomatology. A total of 21 items are rated on a scale from 0 (not present) to 6 (extremely severe) with a total score ranging from 0 to 126. A decrease in score indicates a reduction in psychopathology.
Structure Side-Effect Questionnaire (SSEQ)Through week 16The Structured Side-effect Questionnaire is a simple checklist of 17 side effects. The subject indicates whether a side effect has occurred since the last visit by marking 'yes' or 'no' on the checklist for each of the events listed.
Columbia-Suicide Severity Rating Scale (C-SSRS)Through week 16C-SSRS is a semi-structured interview that captures the occurence, severity, and frequency of suicide-related thoughts and behaviors during the assessment period. The interview includes definitions and suggested questions to solicit the type of information needed to determine if a suicide-related thought or behaviour occurred. The assessment is done by the nature of the responses, not by a numbered scale.
Change From Baseline in the WFIRS-P Life Skills Domain Score at Week 13Baseline and week 13The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Life Skills Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Countries

United States

Participant flow

Participants by arm

ArmCount
PLACEBO
Orally administered a once-daily dose
155
SPD503
Orally administered a once-daily optimal dose between 0.05 mg/kg/day - 0.12 mg/kg/day (up to 7 mg/day depending on weight).
157
Total312

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyAdverse Event39
Overall StudyDeclined Taper Phase01
Overall StudyLack Of Compliance01
Overall StudyLack of Efficacy259
Overall StudyLost to Follow-up411
Overall StudyMissed Visits11
Overall StudyNon Compliance42
Overall StudyPatient Did Not Complete Wk14 and 1501
Overall StudyProtocol Violation31
Overall StudyStopped Taking Meds20
Overall StudyWithdrawal by Subject1316

Baseline characteristics

CharacteristicPLACEBOSPD503Total
Age, Continuous14.6 Years
STANDARD_DEVIATION 1.44
14.5 Years
STANDARD_DEVIATION 1.35
14.5 Years
STANDARD_DEVIATION 1.39
Age, Customized
<18 years
155 Participants157 Participants312 Participants
Region of Enrollment
UNITED STATES
155 Participants157 Participants312 Participants
Sex: Female, Male
Female
56 Participants54 Participants110 Participants
Sex: Female, Male
Male
99 Participants103 Participants202 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
120 / 155147 / 157
serious
Total, serious adverse events
2 / 1554 / 157

Outcome results

Primary

Change From Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 13

The ADHD-RS-IV consists of 18 items scored on a 4-point scale ranging from 0 (no symptoms) to 3 (severe symptoms) with total score ranging from 0 to 54.

Time frame: Baseline through week 13

Population: The Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product. A mixed model repeated measures (MMRM) was used to analyze the observed change from the Baseline Visit scores at all post-baseline, pre-taper, on-treatment visits.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 13-18.527 units on a scaleStandard Error 1.0841
SPD503Change From Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 13-24.552 units on a scaleStandard Error 1.0625
p-value: <0.00195% CI: [-8.865, -3.187]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in Brief Psychiatric Rating Scale for Children (BPRS-C) Total Score at Last On-Treatment Assessment

The BPRS-C characterizes childhood behavioral and emotional symptomatology. A total of 21 items are rated on a scale from 0 (not present) to 6 (extremely severe) with a total score ranging from 0 to 126. A decrease in score indicates a reduction in psychopathology.

Time frame: Baseline and week 13

Population: Safety Population consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (MEAN)Dispersion
PLACEBOChange From Baseline in Brief Psychiatric Rating Scale for Children (BPRS-C) Total Score at Last On-Treatment Assessment-7.0 units on a scaleStandard Deviation 9.85
SPD503Change From Baseline in Brief Psychiatric Rating Scale for Children (BPRS-C) Total Score at Last On-Treatment Assessment-9.1 units on a scaleStandard Deviation 8.11
Secondary

Change From Baseline in Pediatric Daytime Sleepiness Scale (PDSS) Total Score at Week 13

The Pediatric Daytime Sleepiness Scale (PDSS) is an 8 item questionnaire scored on a scale from 0 (never) to 4 (always/very often). Total scores range from 0 to 32, with increasing score reflecting greater sleepiness.

Time frame: Baseline through week 13

Population: Safety Population consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in Pediatric Daytime Sleepiness Scale (PDSS) Total Score at Week 13-3.7 units on a scaleStandard Error 0.52
SPD503Change From Baseline in Pediatric Daytime Sleepiness Scale (PDSS) Total Score at Week 13-4.2 units on a scaleStandard Error 0.51
p-value: 0.46595% CI: [-1.8, 0.8]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Learning and School Domain Scores at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Learning and School Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Learning and School Domain Scores at Week 13-0.457 units on a scaleStandard Error 0.058
SPD503Change From Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Learning and School Domain Scores at Week 13-0.572 units on a scaleStandard Error 0.058
p-value: 0.10495% CI: [-0.254, 0.024]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Academic Performance Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Academic Performance Domain Score at Week 13-0.632 units on a scaleStandard Error 0.096
SPD503Change From Baseline in the WFIRS-P Academic Performance Domain Score at Week 13-0.841 units on a scaleStandard Error 0.096
p-value: 0.08295% CI: [-0.443, 0.026]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Behavior in School Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Behavior in School Domain Score at Week 13-0.376 units on a scaleStandard Error 0.051
SPD503Change From Baseline in the WFIRS-P Behavior in School Domain Score at Week 13-0.459 units on a scaleStandard Error 0.05
p-value: 0.17695% CI: [-0.203, 0.037]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Child Self-Concept Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Child Self-Concept Domain consists of 3-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Child Self-Concept Domain Score at Week 13-0.376 units on a scaleStandard Error 0.067
SPD503Change From Baseline in the WFIRS-P Child Self-Concept Domain Score at Week 13-0.275 units on a scaleStandard Error 0.066
p-value: 0.22895% CI: [-0.064, 0.268]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Family Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Family Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Family Domain Score at Week 13-0.314 units on a scaleStandard Error 0.055
SPD503Change From Baseline in the WFIRS-P Family Domain Score at Week 13-0.371 units on a scaleStandard Error 0.054
p-value: 0.40895% CI: [-0.192, 0.078]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Global Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Global Domain Score at Week 13-0.296 units on a scaleStandard Error 0.036
SPD503Change From Baseline in the WFIRS-P Global Domain Score at Week 13-0.347 units on a scaleStandard Error 0.035
p-value: 0.25395% CI: [-0.136, -0.036]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Life Skills Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Life Skills Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Life Skills Domain Score at Week 13-0.328 units on a scaleStandard Error 0.046
SPD503Change From Baseline in the WFIRS-P Life Skills Domain Score at Week 13-0.375 units on a scaleStandard Error 0.045
p-value: 0.4195% CI: [-0.159, 0.065]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Risk Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Risk Domain consists of 10-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Risk Domain Score at Week 13-0.194 units on a scaleStandard Error 0.027
SPD503Change From Baseline in the WFIRS-P Risk Domain Score at Week 13-0.191 units on a scaleStandard Error 0.026
p-value: 0.91295% CI: [-0.061, 0.068]Mixed Models Repeated Measures Analysis
Secondary

Change From Baseline in the WFIRS-P Social Domain Score at Week 13

The WFIRS-P is a 50-item scale with each item scored from 0 (never/not at all) to 3 (very often/very much). The Social Domain consists of 7-items. Mean scores range from 0 to 3. Higher scores indicate greater functional impairment.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChange From Baseline in the WFIRS-P Social Domain Score at Week 13-0.234 units on a scaleStandard Error 0.046
SPD503Change From Baseline in the WFIRS-P Social Domain Score at Week 13-0.263 units on a scaleStandard Error 0.045
p-value: 0.60695% CI: [-0.139, 0.081]Mixed Models Repeated Measures Analysis
Secondary

Changes From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13

Behavior Rating Inventory of Executive Function (BRIEF) is a questionnaire composed of three indices: Global Executive Composite, Behavioral Regulation Index, and Metacognition Index. Items are rated 1 (never), 2 (sometimes), and 3 (often). The Global Executive Composite consists of 72 items with scoring ranging from 72 to 216. The Behavioral Regulation Index score is the total of 28 items and ranges from 28 to 84. The Metacognition Index score is the total of 44 items and ranges from 44 to 132. Lower scores reflect better functioning.

Time frame: Baseline and week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureGroupValue (LEAST_SQUARES_MEAN)Dispersion
PLACEBOChanges From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13Global Executive Composite-10.6 units on a scaleStandard Error 1.23
PLACEBOChanges From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13Behavioral Regulation Index-11.5 units on a scaleStandard Error 1.29
PLACEBOChanges From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13Metacognition Index-8.9 units on a scaleStandard Error 1.18
SPD503Changes From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13Global Executive Composite-12.9 units on a scaleStandard Error 1.19
SPD503Changes From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13Behavioral Regulation Index-12.4 units on a scaleStandard Error 1.25
SPD503Changes From Baseline in Behavior Rating Inventory of Executive Function (BRIEF) Scores at Week 13Metacognition Index-11.6 units on a scaleStandard Error 1.14
Comparison: Global Executive Compositep-value: 0.13495% CI: [-5.3, 0.7]Mixed Models Repeated Measures Analysis
Comparison: Behavioral Regulation Indexp-value: 0.57995% CI: [-4, 2.3]Mixed Models Repeated Measures Analysis
Comparison: Metacognition Indexp-value: 0.07295% CI: [-5.6, 0.2]Mixed Models Repeated Measures Analysis
Secondary

Columbia-Suicide Severity Rating Scale (C-SSRS)

C-SSRS is a semi-structured interview that captures the occurence, severity, and frequency of suicide-related thoughts and behaviors during the assessment period. The interview includes definitions and suggested questions to solicit the type of information needed to determine if a suicide-related thought or behaviour occurred. The assessment is done by the nature of the responses, not by a numbered scale.

Time frame: Through week 16

Population: Safety Population consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureGroupValue (NUMBER)
PLACEBOColumbia-Suicide Severity Rating Scale (C-SSRS)Suicidal ideation4 participants
PLACEBOColumbia-Suicide Severity Rating Scale (C-SSRS)Suicidal behavior0 participants
SPD503Columbia-Suicide Severity Rating Scale (C-SSRS)Suicidal ideation5 participants
SPD503Columbia-Suicide Severity Rating Scale (C-SSRS)Suicidal behavior0 participants
Secondary

Percent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale at the Last On-Treatment Assessment

CGI-S assesses the severity of the subject's condition on a 7-point scale: 1 (normal, not at all ill), 2 (borderline mentally ill), 3 (mildly ill), 4 (moderately ill), 5 (markedly ill), 6 (severely ill), 7 (among the most extremely ill)

Time frame: Baseline through week 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (NUMBER)
PLACEBOPercent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale at the Last On-Treatment Assessment36.1 percentage of subjects
SPD503Percent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale at the Last On-Treatment Assessment50.6 percentage of subjects
p-value: 0.01Cochran-Mantel-Haenszel
Secondary

Percent of Subjects With Improvement on Clinical Global Impression-Improvement (CGI-I) Scores at the Last On-Treatment Assessment

Clinical Global Impression-Improvement (CGI-I) consists of a 7-point scale ranging from 1 (very much improved) to 7 (very much worse). Improvement is defined as a score of 1 (very much improved) or 2 (much improved) on the scale.

Time frame: weeks 1 through 13

Population: Full Analysis Set consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureValue (NUMBER)
PLACEBOPercent of Subjects With Improvement on Clinical Global Impression-Improvement (CGI-I) Scores at the Last On-Treatment Assessment45.8 percentage of subjects
SPD503Percent of Subjects With Improvement on Clinical Global Impression-Improvement (CGI-I) Scores at the Last On-Treatment Assessment67.5 percentage of subjects
p-value: <0.001Cochran-Mantel-Haenszel
Secondary

Structure Side-Effect Questionnaire (SSEQ)

The Structured Side-effect Questionnaire is a simple checklist of 17 side effects. The subject indicates whether a side effect has occurred since the last visit by marking 'yes' or 'no' on the checklist for each of the events listed.

Time frame: Through week 16

Population: Safety Population consisted of all randomized subjects who took at least 1 dose of investigational product.

ArmMeasureGroupValue (NUMBER)
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Insomnia25 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Missed menses1 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Nausea33 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Vomiting17 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Diarrhea24 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Abdominal pain28 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Decreased appetite42 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Increased appetite47 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Headache53 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Dizziness31 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Fatigue43 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Nervousness/anxiety23 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Somnolence26 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Depression17 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Itching9 participants
PLACEBOStructure Side-Effect Questionnaire (SSEQ)Rash7 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Missed menses4 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Dizziness49 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Depression14 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Nausea37 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Fatigue65 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Vomiting18 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Rash6 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Diarrhea29 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Nervousness/anxiety30 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Abdominal pain30 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Insomnia28 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Decreased appetite48 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Itching11 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Increased appetite42 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Somnolence41 participants
SPD503Structure Side-Effect Questionnaire (SSEQ)Headache76 participants

Source: ClinicalTrials.gov · Data processed: Mar 15, 2026