A Study of TAK-503 in Children and Teenagers With Attention Deficit Hyperactivity Disorder (ADHD)
Public ClinicalTrials.gov record NCT04085172. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
A Phase 4, Multicenter, 2-part Study Composed of a Randomized, Double-blind, Parallel-group, Placebo-controlled, Active-comparator, Dose-optimization Evaluation Followed by a 1-Year Open-label Evaluation to Assess the Safety and Efficacy of Guanfacine Hydrochloride Prolonged-release (SPD503) in Children and Adolescents Aged 6 to 17 Years With Attention-deficit/Hyperactivity Disorder
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
The main aim of this study is learn more about long-term TAK-503 treatment in children and teenagers with ADHD for whom earlier stimulant treatment did not work. The study has two parts (A and B). In Part A, participants will take tablets of TAK-503, atomoxetine or placebo and in Part B TAK-503 tablets.
Study identification
- NCT ID
- NCT04085172
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 4
- Enrollment
- 396 participants
Conditions and interventions
Conditions
Interventions
- Guanfacine hydrochloride (TAK-503) Drug
- Atomoxetine hydrochloride Drug
- Placebo Other
Drug · Other
Eligibility (public fields only)
- Age range
- 6 Years to 17 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Sep 17, 2019
- Primary completion
- Sep 1, 2025
- Completion
- Sep 1, 2025
- Last update posted
- Apr 12, 2026
2019 – 2025
United States locations
- U.S. sites
- 20
- U.S. states
- 13
- U.S. cities
- 20
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Harmonex Neuroscience Research | Dothan | Alabama | 36303 | — |
| Advanced Research Center, Inc. | Anaheim | California | 92805 | — |
| Sun Valley Research Center, Inc. | Imperial | California | 92251 | — |
| Alliance Research | Long Beach | California | 90807 | — |
| PCSD Feighner Research | San Diego | California | 92108 | — |
| Homestead Medical Research | Homestead | Florida | 33030 | — |
| Clinical Neuroscience Solutions, Inc. | Jacksonville | Florida | 32256 | — |
| Care Research Center, Inc. | Miami | Florida | 33130 | — |
| Clinical Neuroscience Solutions, Inc. | Orlando | Florida | 32801 | — |
| AMR Conventions Research, Ltd | Naperville | Illinois | 60563 | — |
| Collective Medical Research LLC | Prairie Village | Kansas | 66208 | — |
| Qualmedica Research, LLC | Bowling Green | Kentucky | 42101 | — |
| Qualmedica Research, LLC | Owensboro | Kentucky | 42301 | — |
| Alivation Research, LLC | Lincoln | Nebraska | 68526 | — |
| Center for Psychiatry and Behavioral Medicine, Inc. | Las Vegas | Nevada | 89128 | — |
| University of Cincinnati | Cincinnati | Ohio | 45219 | — |
| Cutting Edge Research Group | Oklahoma City | Oklahoma | 73116 | — |
| Clinical Neuroscience Solutions, Inc. | Memphis | Tennessee | 38119 | — |
| Family Psychiatry of The Woodlands | The Woodlands | Texas | 77381 | — |
| Clinical Research Partners, LLC | Petersburg | Virginia | 23805 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
Non-U.S. locations
This page focuses on the U.S. directory. The official record also lists 30 non-U.S. sites.
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About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04085172, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Apr 12, 2026 · Synced Sep 1, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04085172 live on ClinicalTrials.gov.