This is a Phase 2, multicenter, randomized, double-blind, placebo-controlled, multi-arm, multi-stage inpatient study designed to assess the efficacy, safety, tolerability, and pharmacokinetics (PK) of NBI-1117568 compared with placebo in adult subjects with a primary diagnosis of schizophrenia, who are experiencing an acute exacerbation or relapse of symptoms.

Key Inclusion Criteria:

• Completed informed consent.
• Subject has a primary diagnosis of schizophrenia.
• The subject is experiencing an acute exacerbation or relapse of symptoms and currently requires hospitalization.
• Subjects taking prohibited medications, including antipsychotics, must discontinue before study participation
• Subject 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:

• An unstable medical condition, chronic disease, or malignancy.
• Considered by the investigator to be at imminent risk of suicide or injury to self or others.
• Diagnosis of moderate or severe substance use disorder (with the exception of nicotine or caffeine dependence) within 6 months prior to screening.
• Positive alcohol test or drug screen for disallowed substances.
• Have a history of poor or suspected poor compliance in clinical research studies and/or in the investigator's opinion, the subject is not capable of adhering to the protocol requirements.