Open-label, Single-dose Trial to Assess the Pharmacokinetics of Centanafadine Extended-release Capsules in Pediatric Participants With Attention-deficit Hyperactivity Disorder (ADHD)

Inclusion criteria

• Written informed consent obtained from a legally acceptable representative and assent obtained from the participant prior to the initiation of any trial-related procedures.
• Male or female participants 9 to 12 years of age, inclusive, at the time of informed consent.
• Participants with documented history of ADHD and confirmation of an ADHD prescription medication.
• Participant is judged by the investigator to be clinically stable and has not had any psychiatric hospitalizations within the past 12 weeks.

Exclusion criteria

• Participants with a history of intellectual disability as determined by at least 1 of the following: intelligence quotient (IQ) < 70, or clinical evidence, or a social or school history that is suggestive of an intellectual disability.
• Participants who have any of the following:

• Significant risk of committing suicide based on history
• Current suicidal behavior
• Imminent risk of injury to self
• Active suicidal ideation
• Any lifetime history of suicidal behavior detected by the "Baseline/Screening" version of the Columbia-Suicide Severity Rating Scale (C-SSRS).
• Participants with a lifetime history of a substance use disorder (as determined by Diagnostic and Statistical Manual of Mental Disorders, 5th Edition [DSM-5] criteria), or current substance misuse including alcohol and benzodiazepines, but excluding caffeine and nicotine.
• Participants with hypothyroidism or hyperthyroidism or an abnormal result for free thyroxine (T4) at screening.
• Participants who currently have clinically significant neurological, dermatological, hepatic, renal, metabolic, hematological, immunological, cardiovascular, pulmonary, or gastrointestinal disorders.
• Participants with insulin-dependent diabetes mellitus.
• Participants with epilepsy or a history of seizures or a history of severe head trauma or cerebrovascular disease.
• Any major surgery within 30 days prior to dosing with the investigational medicinal product (IMP).
• Any history of significant bleeding or hemorrhagic tendencies.
• Blood transfusion within 30 days prior to dosing with IMP.
• Participants with a positive drug screen for cocaine, marijuana (even if by prescription), or other illicit drugs, or alcohol, are excluded and may not be retested or rescreened.
• Participants who have a supine or standing diastolic blood pressure, after resting for at least 5 minutes ≥ 95 mmHg.
• Participants who participated in a clinical trial and were exposed to IMP within the last 30 days prior to screening or who participated in more than 2 interventional clinical trials within the past year.
• Participants with a history of true allergic response to a medication or a history of dermatologic adverse reactions or anaphylaxis secondary to drug exposure.
• Participants who do not tolerate venipuncture or have poor venous access that would cause difficulty when collecting blood samples.
• Relatives of the trial site employees cannot participate in the trial.