Efficacy, Safety & Pharmacokinetic (PK) Study of HLD200 in Children Aged 4-5 Years With ADHD

This is a multicenter, 3 week fixed dose, randomized, double-blind, placebo-controlled, parallel group study to evaluate the efficacy, safety and pharmacokinetics of HLD200 (20 mg and 40 mg) in children aged 4 to 5 years with ADHD. Participants will be screened for eligibility for up to 4 weeks. Eligible participants will be treated with study medication for 3 weeks followed by a 2 week safety follow-up following the end of study treatment. The total duration of the study is up to 9 weeks. A single pharmacokinetic (PK) sample will be taken from each participant, in a prespecified PK sampling window at visit 5, for population PK analysis. A total of 168 participants (56 per treatment arm) will be randomized at Visit 2.