The primary objective for this study is to evaluate the efficacy of NBI-1117570 compared with placebo on improving behavioral and psychological symptoms of schizophrenia in adults who warrant inpatient hospitalization.

Key Inclusion Criteria:

• 18 to 55 years of age
• Primary diagnosis of schizophrenia ≥1 year before screening.
• Participant is experiencing an acute exacerbation or relapse of symptoms with onset less than 2 months before screening and currently requires hospitalization.
• Participant must have had a positive response to at least 1 antipsychotic therapy (other than clozapine) for the treatment of a prior acute relapse.

Key Exclusion Criteria:

• Considered to be at imminent risk of suicide or injury to self or others.
• History of epilepsy, seizures, or convulsions.
• Has orthostatic hypotension, or history of pulmonary hypertension, obstructive coronary artery disease, hypertrophic cardiomyopathy, myocardial infarction, coronary artery revascularization, heart failure, left ventricular hypertrophy, moderate or severe cardiac valvopathy, or other cardiovascular conditions or measures that would preclude participation.
• Currently taking prohibited medications.
• Pregnant or lactating.

Note: Additional inclusion/exclusion criteria may apply, per protocol.