Skip to content

Maintenance of Efficacy of Extended-Release Guanfacine HCl in Children and Adolescents With Attention-deficit/Hyperactivity Disorder (ADHD)

A Phase 3, Double-blind, Placebo-controlled, Multicentre, Randomised Withdrawal, Long-term Maintenance of Efficacy and Safety Study of Extended-release Guanfacine Hydrochloride in Children and Adolescents Aged 6-17 With Attention Deficit/Hyperactivity Disorder

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01081145
Enrollment
528
Registered
2010-03-05
Start date
2010-05-11
Completion date
2013-06-03
Last updated
2021-06-14

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

The primary objective of this study is to evaluate the long-term maintenance of efficacy of Extended-Release Guanfacine HCl in children and adolescents (6-17 years) with attention-deficit/hyperactivity disorder (ADHD) who respond to an initial open-label, short term treatment with SPD503.

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 age and 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 age and 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
6 Years to 17 Years
Healthy volunteers
No

Inclusion criteria

1. Male or female, aged 6-17 years at the time of consent/assent at Screening/Visit 1. 2. Subject's parent or legally authorised representative (LAR) must provide signature of informed consent, and there must be documentation of assent (if applicable) 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) Guideline E6 (1996) and applicable regulations before completing any study-related procedures at Screening/Visit 1. 3. Subject meets DSM-IV-TR criteria for a primary diagnosis of ADHD, combined subtype, hyperactive/impulsive subtype, or inattentive sub-type based on a detailed psychiatric evaluation using the Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime version (K-SADS-PL). 4. Subject has a minimum ADHD-RS-IV total score of 32 at Enrolment/Visit 2. 5. Subject has a minimum CGI-S score of 4 at Enrolment/Visit 2. 6. Subject is functioning at an age-appropriate level intellectually, as deemed by the Investigator. 7. Subject and parent/LAR understand, are willing, able, and likely to fully comply with the study requirements, procedures, and restrictions defined in this protocol. 8. Subject is able to swallow intact tablets. 9. Subject who is a female of child-bearing potential (FOCP), defined as 9 years of age or \<9 years of age and is post-menarchal, must have a negative serum beta Human Chorionic Gonadotropin (hCG) pregnancy test at Screening/Visit 1 and a negative urine pregnancy test at Enrolment/Visit 2 and agree to comply with any applicable contraceptive requirements of the protocol. 10. Subject has a supine and standing BP measurement within the 95th percentile for age, gender, and height.

Exclusion criteria

1. Subject has a current, controlled (requiring a prohibited medication or behavioural modification program) or uncontrolled, comorbid psychiatric diagnosis, except oppositional defiant disorder (ODD), including 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 or lifetime history of bipolar illness, psychosis, or conduct disorder 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/Visit 1 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 with orthostatic hypotension or a known history of controlled or uncontrolled hypertension. 5. Subject has clinically significant ECG findings as judged by the Investigator with consideration of the central ECG laboratory's interpretation. 6. Current use of any prohibited medication or other medications, including herbal supplements, that affect BP or heart rate or that have 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 \[i.e., antihistamines\]) in violation of the protocol specified washout criteria at Enrolment/Visit 2. 7. Subject has used an investigational product within 30 days prior to Enrolment/Visit 2. 8. Subject is significantly overweight based on Centre for Disease Control and Prevention Body Mass Index (BMI)-for-age gender specific charts. Significantly overweight is defined as a BMI \>95th percentile. 9. Children aged 6-12 years with a body weight of \<25kg or adolescents aged 13-17 years with a body weight of \<34kg or \>91kg at Screening/Visit 1. 10. Subject has a known or suspected allergy, hypersensitivity, or clinically significant intolerance to guanfacine hydrochloride or any components found in SPD503. 11. Clinically important abnormality on drug and alcohol screen (excluding the subject's current ADHD stimulant if applicable) at Screening/Visit 1. 12. Subject has a history of alcohol or other substance abuse or dependence, as defined by DSM-IV-TR (with the exception of nicotine) within the last 6 months. 13. Subject is female and is pregnant or currently lactating. 14. Subject failed screening or was previously enrolled in this study. 15. Subject is currently considered a suicide risk in the opinion of the Investigator, has previously made a suicide attempt, or has a prior history of, or is currently demonstrating active suicidal ideation. Subjects with intermittent passive suicidal ideation are not necessarily excluded based on the assessment of the Investigator (see protocol Section 7.2.4.2 for additional guidance). 16. History of failure to respond to an adequate trial of an alpha 2-agonist for the treatment of ADHD (consisting of an appropriate dose and adequate duration of therapy in the opinion of the Investigator). 17. Subject has a history of a seizure disorder (other than a single childhood febrile seizure occurring before the age of 3 years) or the presence of a serious tic disorder (including Tourette's syndrome). 18. Subject has another member of the same household currently participating in this study.

Design outcomes

Primary

MeasureTime frameDescription
Percentage of Participants With Treatment Failures During the Double-Blind Randomized-Withdrawal Phase26 weeksTreatment failure was defined as \>= 50% increase (worsening) in ADHD-RS-IV total score and a \>= 2 point increase (worsening) in CGI-S score compared with the respective scores at the Double-blind Randomized-withdrawal Baseline Visit at 2 consecutive Double-blind Randomized-withdrawal Phase visits. Subjects meeting these criteria were regarded as treatment failures regardless of whether or not they were withdrawn. All subjects who discontinued the study for any reason were regarded as treatment failures for the primary analysis.

Secondary

MeasureTime frameDescription
Change From Double-Blind Randomized-Withdrawal Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - Last Observation Carried Forward (LOCF)Baseline and week 26The 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.
Percent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale During the Double-Blind Randomized-Withdrawal Phase - LOCF26 weeksCGI-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 Double-Blind Randomized-Withdrawal Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Global Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - LOCFBaseline and week 26The 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.
Health Utilities Index-2/3 (HUI 2/3) Scores During the Double-Blind Randomized-Withdrawal Phase - LOCF26 weeksHUI is used to describe health status and to obtain utility scores by collecting data using one or more questionnaires in formats selected to match the specific study design criteria. Scoring ranges from 0.00 (dead) to 1.00 (perfect health). Higher scores represent better health status.
Columbia-Suicide Severity Rating Scale During Double-Blind Randomized-Withdrawal Phase26 weeksC-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 Open-Label Baseline in ADHD-RS-IV Total Score at Week 13 of the Open-Label Phase - LOCFBaseline and 13 weeksThe 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 to Treatment Failure During the Double-Blind Randomized-Withdrawal Phase26 weeksTreatment failure was defined as \>= 50% increase (worsening) in ADHD-RS-IV total score and a \>= 2 point increase (worsening) in CGI-S score compared with the respective scores at the Double-blind Randomized-withdrawal Baseline Visit at 2 consecutive Double-blind Randomized-withdrawal Phase visits. Subjects meeting these criteria were regarded as treatment failures regardless of whether or not they were withdrawn. All subjects who discontinued the study for any reason were regarded as treatment failures for the primary analysis.
Percent of Subjects With Improvement on Clinical Global Impression-Improvement (CGI-I) Scores During Open-Label Phase - LOCF13 weeksClinical 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.
Percent of Subjects With an Assessment of Normal/Borderline Mentally Ill on CGI-S Scale During the Open-Label Phase - LOCF13 weeksCGI-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 Open-Label Baseline in WFIRS-P Global Score at Week 13 of the Open-Label Phase - LOCFBaseline 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.
HUI 2/3 Scores During the Open-Label Phase - LOCF13 weeksHUI is used to describe health status and to obtain utility scores by collecting data using one or more questionnaires in formats selected to match the specific study design criteria. Scoring ranges from 0.00 (dead) to 1.00 (perfect health). Higher scores represent better health status.
Columbia-Suicide Severity Rating Scale During Open-Label Phase13 weeksC-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.
Percentage of Responders in the Open-Label Phase - LOCF13 weeksResponse is defined as a percentage decrease (improvement) from Baseline in the ADHD-RS-IV total score of \>=30% and a CGI-S score of 1 or 2.

Countries

Belgium, Canada, France, Germany, Italy, Netherlands, Spain, Sweden, United Kingdom, United States

Participant flow

Participants by arm

ArmCount
Guanfacine Hydrochloride
Administered as a once-daily oral dose between 1-7mg/day depending on age and weight
526
Total526

Withdrawals & dropouts

PeriodReasonFG000FG001
Double-Blind Randomized-Withdrawal PhaseAdverse Event32
Double-Blind Randomized-Withdrawal PhaseLack of Efficacy1320
Double-Blind Randomized-Withdrawal PhaseLost to Follow-up32
Double-Blind Randomized-Withdrawal PhaseOther43
Double-Blind Randomized-Withdrawal PhaseProtocol Violation10
Double-Blind Randomized-Withdrawal PhaseTreatment failure criteria met4771
Double-Blind Randomized-Withdrawal PhaseWithdrawal by Subject108
Open-Label PhaseAdverse Event420
Open-Label PhaseLack of Efficacy560
Open-Label PhaseLost to Follow-up110
Open-Label PhaseOther120
Open-Label PhaseProtocol Violation40
Open-Label PhaseResponse criteria not met460
Open-Label PhaseWithdrawal by Subject410

Baseline characteristics

CharacteristicGuanfacine Hydrochloride
Age, Continuous10.7 Years
STANDARD_DEVIATION 2.7
Age, Customized
13-17 years
135 Participants
Age, Customized
6-12 years
391 Participants
Region of Enrollment
BELGIUM
19 Participants
Region of Enrollment
CANADA
30 Participants
Region of Enrollment
FRANCE
14 Participants
Region of Enrollment
GERMANY
27 Participants
Region of Enrollment
ITALY
31 Participants
Region of Enrollment
NETHERLANDS
29 Participants
Region of Enrollment
SPAIN
68 Participants
Region of Enrollment
SWEDEN
5 Participants
Region of Enrollment
UNITED KINGDOM
25 Participants
Region of Enrollment
UNITED STATES
278 Participants
Sex: Female, Male
Female
130 Participants
Sex: Female, Male
Male
396 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
— / —— / —— / —
other
Total, other adverse events
423 / 52651 / 15865 / 157
serious
Total, serious adverse events
5 / 5264 / 1582 / 157

Outcome results

Primary

Percentage of Participants With Treatment Failures During the Double-Blind Randomized-Withdrawal Phase

Treatment failure was defined as \>= 50% increase (worsening) in ADHD-RS-IV total score and a \>= 2 point increase (worsening) in CGI-S score compared with the respective scores at the Double-blind Randomized-withdrawal Baseline Visit at 2 consecutive Double-blind Randomized-withdrawal Phase visits. Subjects meeting these criteria were regarded as treatment failures regardless of whether or not they were withdrawn. All subjects who discontinued the study for any reason were regarded as treatment failures for the primary analysis.

Time frame: 26 weeks

Population: Randomized Full Analysis Set (FAS) defined as all subjects who were randomized and took at least 1 dose of investigational product during the Double-blind Randomized-withdrawal Phase. Subjects from Site 801 were excluded from the Randomized FAS.

ArmMeasureValue (NUMBER)
PlaceboPercentage of Participants With Treatment Failures During the Double-Blind Randomized-Withdrawal Phase64.9 percentage of treatment failures
Guanfacine HydrochloridePercentage of Participants With Treatment Failures During the Double-Blind Randomized-Withdrawal Phase49.3 percentage of treatment failures
p-value: 0.00695% CI: [-26.6, -4.5]Cochran-Mantel-Haenszel
Secondary

Change From Double-Blind Randomized-Withdrawal Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - Last Observation Carried Forward (LOCF)

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 and week 26

Population: Randomized FAS

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PlaceboChange From Double-Blind Randomized-Withdrawal Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - Last Observation Carried Forward (LOCF)15.89 units on a scaleStandard Error 1.225
Guanfacine HydrochlorideChange From Double-Blind Randomized-Withdrawal Baseline in Attention Deficit Hyperactivity Disorder Rating Scale-fourth Edition (ADHD-RS-IV) Total Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - Last Observation Carried Forward (LOCF)9.64 units on a scaleStandard Error 1.21
p-value: <0.00195% CI: [-9.01, -3.48]ANCOVA
Secondary

Change From Double-Blind Randomized-Withdrawal Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Global Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - LOCF

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 26

Population: Randomized FAS

ArmMeasureValue (LEAST_SQUARES_MEAN)Dispersion
PlaceboChange From Double-Blind Randomized-Withdrawal Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Global Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - LOCF0.23 units on a scaleStandard Error 0.036
Guanfacine HydrochlorideChange From Double-Blind Randomized-Withdrawal Baseline in the Weiss Functional Impairment Rating Scale - Parent Report (WFIRS-P) Global Score at Week 26 of the Double-Blind Randomized-Withdrawal Phase - LOCF0.16 units on a scaleStandard Error 0.035
p-value: 0.11895% CI: [-0.14, 0.02]ANCOVA
Secondary

Change From Open-Label Baseline in ADHD-RS-IV Total Score at Week 13 of the Open-Label Phase - LOCF

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 and 13 weeks

Population: Open-label Full Analysis Set (FAS) defined as all subjects who took at least 1 dose of any investigational product during the study. The Subjects from Site 801 were excluded from the Open-label FAS.

ArmMeasureValue (MEAN)Dispersion
PlaceboChange From Open-Label Baseline in ADHD-RS-IV Total Score at Week 13 of the Open-Label Phase - LOCF-25.2 units on a scaleStandard Deviation 11.97
p-value: <0.001t-test, 2 sided
Secondary

Change From Open-Label Baseline in WFIRS-P Global Score at Week 13 of the Open-Label Phase - LOCF

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: Open-label FAS

ArmMeasureValue (MEAN)Dispersion
PlaceboChange From Open-Label Baseline in WFIRS-P Global Score at Week 13 of the Open-Label Phase - LOCF-0.35 units on a scaleStandard Deviation 0.414
p-value: <0.001t-test, 2 sided
Secondary

Columbia-Suicide Severity Rating Scale During Double-Blind Randomized-Withdrawal Phase

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: 26 weeks

Population: Randomized Safety Population defined as all subjects who were randomized and who took at least 1 dose of investigational product during the Double-blind Randomized-withdrawal Phase.

ArmMeasureGroupValue (NUMBER)
PlaceboColumbia-Suicide Severity Rating Scale During Double-Blind Randomized-Withdrawal PhaseSuicidal ideation2 participants
PlaceboColumbia-Suicide Severity Rating Scale During Double-Blind Randomized-Withdrawal PhaseSuicidal behavior0 participants
Guanfacine HydrochlorideColumbia-Suicide Severity Rating Scale During Double-Blind Randomized-Withdrawal PhaseSuicidal ideation2 participants
Guanfacine HydrochlorideColumbia-Suicide Severity Rating Scale During Double-Blind Randomized-Withdrawal PhaseSuicidal behavior0 participants
Secondary

Columbia-Suicide Severity Rating Scale During Open-Label Phase

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: 13 weeks

Population: Open-label Safety Population defined as all subjects who took at least 1 dose of any investigational product during the study.

ArmMeasureGroupValue (NUMBER)
PlaceboColumbia-Suicide Severity Rating Scale During Open-Label PhaseSuicidal ideation1 participants
PlaceboColumbia-Suicide Severity Rating Scale During Open-Label PhaseSuicidal behavior2 participants
Secondary

Health Utilities Index-2/3 (HUI 2/3) Scores During the Double-Blind Randomized-Withdrawal Phase - LOCF

HUI is used to describe health status and to obtain utility scores by collecting data using one or more questionnaires in formats selected to match the specific study design criteria. Scoring ranges from 0.00 (dead) to 1.00 (perfect health). Higher scores represent better health status.

Time frame: 26 weeks

Population: Randomized FAS

ArmMeasureValue (MEAN)Dispersion
PlaceboHealth Utilities Index-2/3 (HUI 2/3) Scores During the Double-Blind Randomized-Withdrawal Phase - LOCF0.899 units on a scaleStandard Deviation 0.1272
Guanfacine HydrochlorideHealth Utilities Index-2/3 (HUI 2/3) Scores During the Double-Blind Randomized-Withdrawal Phase - LOCF0.900 units on a scaleStandard Deviation 0.1229
Secondary

HUI 2/3 Scores During the Open-Label Phase - LOCF

HUI is used to describe health status and to obtain utility scores by collecting data using one or more questionnaires in formats selected to match the specific study design criteria. Scoring ranges from 0.00 (dead) to 1.00 (perfect health). Higher scores represent better health status.

Time frame: 13 weeks

Population: Open-label FAS

ArmMeasureValue (MEAN)Dispersion
PlaceboHUI 2/3 Scores During the Open-Label Phase - LOCF0.892 units on a scaleStandard Deviation 0.123
Secondary

Percentage of Responders in the Open-Label Phase - LOCF

Response is defined as a percentage decrease (improvement) from Baseline in the ADHD-RS-IV total score of \>=30% and a CGI-S score of 1 or 2.

Time frame: 13 weeks

Population: Open-label FAS

ArmMeasureValue (NUMBER)
PlaceboPercentage of Responders in the Open-Label Phase - LOCF68.6 percentage of participants
Secondary

Percent of Subjects With an Assessment of Normal/Borderline Mentally Ill on CGI-S Scale During the Open-Label Phase - LOCF

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: 13 weeks

Population: Open-label FAS

ArmMeasureValue (NUMBER)
PlaceboPercent of Subjects With an Assessment of Normal/Borderline Mentally Ill on CGI-S Scale During the Open-Label Phase - LOCF68.9 percentage of participants
Secondary

Percent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale During the Double-Blind Randomized-Withdrawal Phase - LOCF

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: 26 weeks

Population: Randomized FAS

ArmMeasureValue (NUMBER)
PlaceboPercent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale During the Double-Blind Randomized-Withdrawal Phase - LOCF32.5 percentage of subjects
Guanfacine HydrochloridePercent of Subjects With an Assessment of Normal/Borderline Mentally Ill on Clinical Global Impression-Severity of Illness (CGI-S) Scale During the Double-Blind Randomized-Withdrawal Phase - LOCF50.0 percentage of subjects
p-value: 0.00195% CI: [6.6, 28.5]Cochran-Mantel-Haenszel
Secondary

Percent of Subjects With Improvement on Clinical Global Impression-Improvement (CGI-I) Scores During Open-Label Phase - LOCF

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: 13 weeks

Population: Open-label FAS

ArmMeasureValue (NUMBER)
PlaceboPercent of Subjects With Improvement on Clinical Global Impression-Improvement (CGI-I) Scores During Open-Label Phase - LOCF76.1 percentage of participants
Secondary

Time to Treatment Failure During the Double-Blind Randomized-Withdrawal Phase

Treatment failure was defined as \>= 50% increase (worsening) in ADHD-RS-IV total score and a \>= 2 point increase (worsening) in CGI-S score compared with the respective scores at the Double-blind Randomized-withdrawal Baseline Visit at 2 consecutive Double-blind Randomized-withdrawal Phase visits. Subjects meeting these criteria were regarded as treatment failures regardless of whether or not they were withdrawn. All subjects who discontinued the study for any reason were regarded as treatment failures for the primary analysis.

Time frame: 26 weeks

Population: Randomized FAS

ArmMeasureValue (MEDIAN)
PlaceboTime to Treatment Failure During the Double-Blind Randomized-Withdrawal Phase56.0 Days
Guanfacine HydrochlorideTime to Treatment Failure During the Double-Blind Randomized-Withdrawal Phase218.0 Days
p-value: 0.003Log Rank

Source: ClinicalTrials.gov · Data processed: Mar 14, 2026