CI

At a glance

ClinicalIndex Comparison Record
Phase 4Completed· 396 enrolled
Drug / intervention
Guanfacine hydrochloride (TAK-503) +2 moredrug
Likely dose
Guanfacine hydrochloride (TAK-503) 4 mgfrom record
Structured eligibility isn't available for this trial yet — see the full criteria in the Eligibility tab below.

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT04085172
NCT04085172Phase 4Completed

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

Shire·interventional·Posted Sep 11, 2019·Updated Apr 13, 2026

In Brief

A Phase 4 clinical trial evaluating Guanfacine hydrochloride (TAK-503), Atomoxetine hydrochloride, and 1 other intervention for Attention Deficit Hyperactivity Disorder. Completed, enrolled 396 participants across 50 sites in 9 countries.

Detailed Summary

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 Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesAustria, Belgium, Germany, Netherlands, Portugal, Spain, Sweden, United Kingdom, United States

Timeline

Phase 4CompletedFinished
2020202120222023202420252026
First PostedSep 11, 2019
Enrollment StartSep 18, 2019
Primary CompletionSep 2, 2025
TodayJul 2, 2026
Enrollment to primary: 6.0 yearsPosted 6.8 years ago

Interventions

Guanfacine hydrochloride (TAK-503)drug

Participants aged 6 to 12 years will receive a dose of 1 to 4 mg and aged 13 to 17 years will receive a dose of 5 to 7 mg TAK-503 oral tablets once daily for 18 weeks in Part A or 52 weeks in Part B.

Atomoxetine hydrochloridedrug

Participants will receive Atomoxetine hydrochloride oral capsule once daily for 18 weeks in Part A.

Placeboother

Participants aged 6 to 12 years will receive a dose of 1 to 4 mg and aged 13 to 17 years will receive a dose of 5 to 7 mg placebo matched to TAK 503 oral tablets once daily for 18 weeks and placebo matched to atomoxetine hydrochloride oral capsules at once daily for 18 weeks in Part A.