ADZENYS XR-ODT™ in Children (4 to <6 Years) Diagnosed With Attention-deficit/Hyperactivity Disorder

This randomized, double-blind, flexible-dose, placebo-controlled, parallel group study is designed to evaluate the efficacy, safety, and tolerability of ADZENYS XR-ODT compared to placebo in children with ADHD. Male and female children ages 4 to less than 6 years with a diagnosis of ADHD based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria (combined, inattentive, or hyperactive/impulsive) will be enrolled. A Screening/Washout Period of up to 4 weeks (Days -28 to -1), which will include washout of any current ADHD medications (if applicable), will be followed by an 8-week, Randomized, Double-blind, Flexible-dose Period during which subjects will be randomly assigned to placebo or to ADZENYS XR-ODT once daily. All subjects will start on 3.1 mg of ADZENYS XR-ODT or matching placebo. The dose for each subject will be titrated in a stepwise fashion each week from Visit 3 to Visit 8 (Weeks 1 to 6) based on efficacy and tolerability to 6.3 mg; 9.4 mg; 12.5 mg; 15.7 mg; and 18.8 mg once daily, until an optimal dose or the highest dose is reached. No subject will receive a dose higher than 18.8 mg/day. Subjects must remain on a stable dose for at least 2 weeks. An optimal dose is one that produces a reduction from Baseline of ADHD symptoms (ADHD Rating Scale IV \[ADHD-RS-IV\] Preschool Version) of ≥30% and a Clinical Global Impression Severity (CGI-S) score of 1 (normal), 2 (borderline ill), or 3 (mildly ill), while maintaining a tolerable adverse event (AE) profile. Once subjects reach an optimal dose of study drug, they will continue on that dose for the remainder of the study. During titration, if a higher dose is not tolerated, the investigator may reduce the subject's dose by 1 dose level (this may not be done after Week 6 \[Visit 8\] of the study). If further dose reductions are required, the subject should be discontinued from the study. Subjects who are unable to tolerate the lowest daily dose (3.1 mg) of study drug will be discontinued from the study. Subjects who complete the 8-week Treatment Period may be eligible to enter the long-term safety and tolerability study of ADZENYS XR-ODT (NT0202.1010). For subjects to be eligible, they must complete Visit 10 without experiencing any clinically significant AEs that would preclude further exposure to ADZENYS XR-ODT. For subjects entering Study NT0202.1010, Visit 10 of this study can be Visit 1 of Study NT0202.1010, unless more than 2 weeks have elapsed since Visit 10. A safety follow-up telephone call will be made to parents/legal guardians approximately 1 week after discontinuation of study drug for subjects who do not roll over into Study NT0202.1010.