A Study to Test the Effects of Centanafadine in Adults With Attention-deficit/Hyperactivity Disorder and Emotional Dysregulation

A Phase 3b, Multicenter, Open-label, Single-arm Trial to Evaluate the Efficacy and Safety of Orally Administered Centanafadine QD XR Capsules in Adults With Attention-deficit/Hyperactivity Disorder and Emotional Dysregulation

The primary purpose of this study is to evaluate the efficacy of centanafadine once daily (QD) extended-release (XR) capsules in adults with attention-deficit/hyperactivity disorder (ADHD) and emotional dysregulation (ED).

Study Overview

• Status: Not yet recruiting
• Conditions: Attention-deficit/Hyperactivity Disorder; Emotional Dysregulation
• Intervention / Treatment: Drug: Centanafadine XR

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Otsuka Call Center; Phone Number: 844-687-8522; Email: Otsuka-ProfessionalServices@otsuka-us.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria

1. Primary diagnosis of ADHD per the Adult ADHD Clinical Diagnostic Scale (ACDS).
2. Adult ADHD Investigator Symptom Rating Scale (AISRS) total score of ≥ 28 at baseline.
3. Symptoms of ED as determined by the WRAADDS-ED subscale score ≥ 7 at baseline.
4. CGI-S-ADHD rating ≥ 4 (at least moderate severity) at baseline.

Exclusion Criteria

1. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for a lifetime diagnosis of bipolar and related disorders, schizophrenia spectrum and other psychotic disorders, borderline and antisocial personality disorders, neurocognitive disorders, autism spectrum disorder, or intellectual disability.
2. DSM-5 criteria for a current diagnosis of major depressive disorder, post-traumatic stress disorder, any substance use disorder, untreated/unstable obstructive sleep apnea, eating disorders, or obsessive compulsive disorder.
3. Any other current DSM-5 comorbid psychiatric disorder identified by the Mini International Neuropsychiatric Interview (MINI) or any medical condition that, in the judgment of the investigator, could be expected to require treatment with medications prohibited in this trial that cannot be safely discontinued with completion of an appropriate washout, could confound efficacy or safety assessments, or be the primary driver of ED.
4. Presence of an unstable or uncontrolled medical condition that, in the opinion of the investigator, could pose a safety risk to the participant or could manifest with psychiatric symptoms (eg, thyroid disease).
5. In the clinical opinion of the investigator, the participant has not derived significant therapeutic benefit from 2 or more ADHD therapies of 2 different classes (eg, amphetamine and methylphenidate, or amphetamine and atomoxetine) given with an acceptable dose and duration during adulthood (aged 18 years or older).
6. Current use of prohibited psychotropic medications that cannot be discontinued within 7 to 28 days prior to enrollment.
7. Any disorder that is the primary focus of treatment other than ADHD.
8. Evidence of current substance use disorder or history in the past 12 months.
9. History of any prior exposure to centanafadine.
10. Participated in other clinical trials involving investigational drugs within 180 days prior to screening or participated in more than 2 interventional clinical trials involving investigational drugs within the past year.
11. Have an allergy to the IMP or any component of the IMP.

Note: Other protocol-specified inclusion/exclusion criteria may apply.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Centanafadine XR; Participants will receive centanafadine XR capsule 328.8 milligrams (mg), orally, QD, for 8 weeks.	Drug: Centanafadine XR; Oral capsules; Other Names: EB-1020

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change From Baseline to Week 8 in the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS) Total Score	Baseline up to Week 8

Secondary Outcome Measures

Outcome Measure	Time Frame
Change From Baseline to Week 8 in the Wender-Reimherr Adult Attention Deficit Disorder Scale Emotional Dysregulation (WRAADDS-ED) Subscale Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Clinical Global Impressions-Severity Scale for Attention-Deficit/Hyperactivity Disorder (CGI-S-ADHD) Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) T-score for the Global Executive Composite (GEC) Scale	Baseline up to Week 8
Change From Baseline to Week 8 in the BRIEF-A T-score for the Behavioral Regulation Index (BRI) Scale	Baseline up to Week 8
Change From Baseline to Week 8 in the BRIEF-A T-score for the Metacognition Index (MI) Scale	Baseline up to Week 8
Change From Baseline to Week 8 in the Difficulties in Emotion Regulation Scale (DERS) Total Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Nonacceptance of Emotional Responses (NONACCEPT) DERS Subscale Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Difficulties Engaging in Goal-Directed Behavior (GOALS) DERS Subscale Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Impulse Control Difficulties (IMPULSE) DERS Subscale Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Lack of Emotional Awareness (AWARE) DERS Subscale Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Limited Access to Emotion Regulation Strategies (STRATEGIES) DERS Subscale Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Lack of Emotional Clarity (CLARITY) DERS Subscale Score	Baseline up to Week 8
Change From Baseline to Week 8 in the Attention-Deficit/Hyperactivity Disorder Symptoms, Executive Function Deficits, and Emotional Dyscontrol as Assessed by the Adult ADHD Self-Report Scale (ASRS) Score	Baseline up to Week 8
Number of Participants With Adverse Events	Up to Week 9
Number of Participants With Suicidal Ideation or Behavior as Assessed by the Columbia-Suicide Severity Rating Scale (C-SSRS)	Up to Week 9

Collaborators and Investigators

• Sponsor: Otsuka Pharmaceutical Development & Commercialization, Inc.

Publications and helpful links

Helpful Links

• Otsuka Clinical Trial Website
• Otsuka Clinical Trial Transparency

Study record dates

Study Major Dates

• Study Start (Estimated): August 20, 2026
• Primary Completion (Estimated): May 27, 2027
• Study Completion (Estimated): May 27, 2027

Study Registration Dates

• First Submitted: August 6, 2026
• First Submitted That Met QC Criteria: August 6, 2026
• First Posted (Actual): August 12, 2026

Study Record Updates

• Last Update Posted (Actual): August 12, 2026
• Last Update Submitted That Met QC Criteria: August 6, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: ADHD; ED
• Additional Relevant MeSH Terms: Mental Disorders; Neurodevelopmental Disorders; Attention Deficit and Disruptive Behavior Disorders; Attention Deficit Disorder with Hyperactivity; 1-(naphthalen-2-yl)-3-azabicyclo(3.1.0)hexane
• Other Study ID Numbers: 405-201-00231

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Anonymized individual participant data (IPD) that underlie the results of this study will be shared with researchers to achieve aims pre-specified in a methodologically sound research proposal. Small studies with less than 25 participants are excluded from data sharing.
• IPD Sharing Time Frame: Data will be available after marketing approval in global markets, or beginning 1-3 years following article publication. There is no end date to the availability of the data.
• IPD Sharing Access Criteria: Otsuka will share data on the Vivli data sharing platform: https://vivli.org/ourmember/Otsuka/
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No