This study is about testing a medicine called Brilaroxazine (also known as RP5063) to help people with schizophrenia. Schizophrenia is a serious mental health condition that affects how a person thinks, feels, and behaves. The study will compare Brilaroxazine to a placebo (a pill with no medicine) to see if it is safe and works well.

For the first part, participants take a fixed dose every day for 4 weeks. After that, the dose can change, and they take it for another 52 weeks. This is a randomized study, meaning participants are randomly chosen for either the medicine or placebo. It is also double-blind, which means neither the doctor nor the participant knows which pill they are taking.

• The study lasts 56 weeks in total.
• Participants must be between 18 and 65 years old.
• Participants cannot join if they have a history of certain treatments or conditions.

Before joining, participants will need to sign a form showing they understand the study.