Clinical Research Directory

Inclusion Criteria: 1. Male and female volunteers 18-55 years of age, inclusive at screening. 2. Has a primary diagnosis of schizophrenia, for ≥ 1 year 3. Stable schizophrenia psychiatric symptoms for at least 6 weeks prior to screening. 4. Schizophrenia clinical symptom severity defined by meeting ALL of the following per the Positive and Negative Syndrome Scale (PANSS) item scores at screening: 1. Delusions (P1) ≤ 4 2. Hallucinatory behavior (P3) ≤ 4 3. Unusual thought content (G9) ≤ 4 4. Hostility (P7) ≤ 4 5. Patient has a PANSS total score ≤ 80 at screening and baseline visits and no worsening in PANSS total score between screening and baseline, of more than 20%. 6. Has a Brief Assessment of Cognition (BACS) T-score \< 50 at the screening visit. 7. On a stable regimen of at least one and up to a maximum of two second-generation ("atypical") antipsychotic medications for at least 6 weeks prior to screening and agree to stay on this regimen for their entire study participation, with the following exceptions: 1. Clozapine use is not permitted 2. Quetiapine for sleep at doses less than 300 mg are permitted. 3. Day time (including morning) quetiapine use as the background antipsychotic is not permitted. 8. Able to understand the requirements of the study and able and willing to provide written informed consent and to abide by the study procedures, in the judgment of the Investigator, including able and willing to remain in an in-patient setting during the study. 9. If of childbearing potential, using adequate contraceptive methods for the duration of the study. 10. Body mass index of 18.5 to 40.0 kg/m2 (inclusive) and total body weight \> 50 kg (110 lbs.) for males and \> 40 kg (88 lbs.) for females. 11. Has a negative urine screen for drugs of abuse and negative alcohol breath test at screening and check-in. 12. Patient resides in a stable living situation and is anticipated to return to that same stable living situation. Exclusion Criteria: 1. Participation in a schizophrenia study in which the patient has received any investigational medications within 60 days prior to the baseline visit. 2. History or presence of a clinically significant, poorly treated, or unstable conditions that would jeopardize the safety of the patient or the validity of the study results. 3. Clinically significant abnormal findings on the physical examination, medical history, ECG, or clinical laboratory results at screening. 4. Calgary Depression Scale for schizophrenia (CDSS) score ≥6 at the screening or baseline visits. 5. Simpson Angus Scale (SAS) total score ≥5 at the screening and baseline visits at the screening or baseline visits. 6. Abnormal Involuntary Movement (AIMS) score of 2 for two or more movements or a score of 3 or 4 for any single movement on this scale at the screening or baseline visits. 7. Any primary the DSM-5-TR (American Psychiatric Association 2022) disorder other than schizophrenia within 12 months before screening (confirmed using MINI version 7.0.2 at screening). 8. Pregnant, lactating, or less than 3 months postpartum. Sperm donation is not allowed for 90 days after the final dose of study drug. 9. Risk for suicidal behavior during the study. 10. Inability to detect a 1000 Hz tone at 40 dB in both ears at screening. 11. Has psychiatric hospitalization(s) for more than 30 days (cumulative) during the 90 days before screening.