The primary objective for this study is to evaluate the efficacy of NBI-1117568 compared with placebo on improving behavioral and psychological symptoms of schizophrenia in adults.

Key Inclusion Criteria:

• Participant has a primary diagnosis of schizophrenia
• Participant is experiencing an acute exacerbation or relapse of symptoms and currently warrants hospitalization.
• Participants taking prohibited medications, including antipsychotics, must discontinue before study participation
• Participant is willing and able to remain in an inpatient setting for the study duration, follow instructions, and comply with the protocol requirements

Key Exclusion Criteria:

• Participant has known hypersensitivity to any component of the formulation of NBI-1117568
• Participant has an unstable or poorly controlled medical condition or chronic disease
• Participant is considered by the investigator to be at imminent risk of suicide or injury to self or others
• Participant has a diagnosis of moderate or severe substance use disorder (with the exception of nicotine or caffeine dependence) within 6 months prior to screening
• Participant has a positive alcohol test or drug screen for disallowed substances
• Participant has a history of poor or suspected poor compliance in clinical research studies and/or in the investigator's opinion, the participant is not capable of adhering to the protocol requirements.

Note: Other protocol-specified inclusion/exclusion criteria may apply.