A Study to Evaluate 3 Dose Levels of Luvadaxistat of Adults With Negative Symptoms of Schizophrenia

Exclusion Criteria

• •1. Has a lifetime diagnosis of schizoaffective disorder; a lifetime diagnosis of bipolar disorder; or a lifetime diagnosis of obsessive compulsive disorder based on the MINI combined with the general psychiatric evaluation.
• •2. Has a recent (within the last 6 months) occurrence of panic disorder, depressive episode, or other comorbid psychiatric conditions currently requiring clinical attention based on the MINI for DSM-5 and the general psychiatric evaluation.
• •3. Has a diagnosis of substance use disorder (with the exception of nicotine dependence) within the preceding 6 months based on the MINI for DSM-5 and the general psychiatric evaluation.
• •4. Is participating in a formal structured nonpharmacological psychosocial therapeutic treatment program (cognitive remediation, cognitive-behavioral therapy, intensive symptom/vocational rehabilitation) for a duration of less than (\<) 3 months before randomization. In addition, initiation of such nonpharmacological treatment programs is not permitted during study participation through the Day 84 visit.
• •5. The participant exhibits more than a minimal level of antipsychotic-induced parkinsonism symptoms, as documented by a score on the modified Simpson Angus Scale (SAS) (excluding item number 10, Akathisia) greater than (\>) 6.
• •6. Has evidence of depression as measured by a Calgary Depression Scale Score (CDSS) \> 9.
• •7. Is considered by the investigator to be at imminent risk of suicide or injury to self, others, or property, or the participant has attempted suicide within the past year prior to screening. Participants who have positive answers on item number 4 or 5 on the Columbia-Suicide Severity Rating Scale (C-SSRS) (based on the past year) prior to randomization are excluded.
• •8. Has a history of brain trauma associated with loss of consciousness for \>15 minutes.
• •9. Diagnosis of schizophrenia occurred prior to 12 years of age.
• •10. Has received electroconvulsive therapy within 6 months (180 days) before Screening.
• •11. Has a history of developmental intellectual disability or mental retardation.
• •12. Antipsychotic plasma levels for the participant's primary background antipsychotic are below the minimum acceptable concentration criteria per the Antipsychotic Reference document at the screening or placebo run-in visits. This criterion is not applicable to participants on a primary background antipsychotic for which a clinical assay is unavailable.
• •13. Is treatment resistant. Treatment resistance is defined as prior nonresponse of positive symptoms of schizophrenia to 2 courses of treatment with antipsychotics of different chemical classes for at least 4 weeks, each at doses considered to be effective.
• •14. Does not have a stable residence or is homeless.