This study is for children and teens aged 5 to 17 with autism spectrum disorder (ASD) who experience irritability. **Autism Spectrum Disorder (ASD)** is a condition affecting how a person communicates and interacts with others. **Irritability** means getting upset or angry easily. The study tests a drug called **lumateperone** to see if it helps with irritability.
There are three parts to the study:
- Screening Period: Up to 14 days to see if the patient can join the study.
- Double-blind Treatment Period: 6 weeks where patients get either a high dose, low dose of lumateperone, or a placebo (a pill with no medicine) once a day.
- Safety Follow-up Period: A week after stopping the study drug, patients will have a safety check.
To join, a parent or guardian must agree to participate and attend visits. The child must be 13 to 17 years old and meet specific tests for ASD. Those with other main psychiatric issues, except ADHD, or at risk of self-harm, cannot join.
- Study lasts about 9 weeks in total.
- Participants must attend several visits to the clinic.
- Safety and health will be closely monitored throughout.