The primary objective is to evaluate the efficacy of lumateperone administered orally for at least 26 weeks in pediatric patients with schizophrenia (aged 13 to 17 years) or pediatric patients with bipolar disorder (aged 10 to 17 years), or pediatric patients with irritability associated with autism spectrum disorder (ASD) (aged 5 to 17 years).

The primary objective is to evaluate the efficacy of high and low doses of lumateperone vs placebo for the treatment of irritability associated with autism spectrum disorder (ASD) in pediatric patients as measured by the change from baseline to end of Week 6 in the ABC Irritability (ABC-I) subscale score.