Evaluating clozapine's effectiveness in specific psychosis patients

Antipsychotic Response to Clozapine in B-SNIP Biotype-1 (Clozapine)

Phase 4 Interventional University of Texas Southwestern Medical Center · NCT04580134

This study is testing if clozapine works better than risperidone for people with schizophrenia, schizoaffective disorder, and bipolar I disorder who have a specific brain activity pattern.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment524 (estimated)
Ages18 Years to 60 Years
SexAll
SponsorUniversity of Texas Southwestern Medical Center Academic / other
Locations5 sites (Hartford, Connecticut and 4 other locations)
Trial IDNCT04580134 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the response to clozapine in individuals with schizophrenia, schizoaffective disorder, and bipolar I disorder who are classified as Biotype-1. The study employs a randomized, double-blinded, parallel group design across five sites, comparing clozapine's effects against risperidone in a controlled setting. The researchers aim to determine if Biotype-1 patients, characterized by low Intrinsic EEG Activity, show a unique therapeutic response to clozapine, which may differ from the response of Biotype-2 patients. A total of 320 participants will be enrolled from an initial screening of 524 individuals with psychosis.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18-60 with schizophrenia, schizoaffective disorder, or bipolar I disorder with psychotic features.

Not a fit: Patients with a history of substance abuse, severe medical conditions, or low premorbid intellectual ability may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to more effective treatment options for patients with specific types of psychosis.

How similar studies have performed: Previous studies have indicated that specific patient biotypes may respond differently to antipsychotic medications, suggesting potential for success in this novel approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 18-60y/o; males and females; all races and ethnicities; able to provide written informed consent; able to read, speak, and understand English; medically stable; meeting DSM-IV (SCID-based) criteria for schizophrenia, schizoaffective disorder, or bipolar I disorder with psychotic features (we will use DSM-IV to be consistent with prior B-SNIP samples); PANSS total score of ≥70 and at least one item scored ≥5 or two items scored ≥4 on PANSS Positive Subscale; normal baseline values for absolute neutrophil count (ANC above 1500/mm3)

Exclusion Criteria:

* premorbid intellectual ability estimate below 70 (WRAT-4, Word Reading subtest, age-corrected standardized score); comorbid DSM-IV diagnosis of alcohol or substance abuse in prior 1 month or substance dependence in prior 3 months; neurological (e.g., seizure disorder, stroke, traumatic brain injury with a loss of consciousness ≥ 30min) or severe medical condition (e.g., decompensated cardiovascular disorder, AIDS) that may affect central nervous system function; concomitant medications known to affect EEG properties (i.e., lithium, anticonvulsants, benzodiazepines) or strong CYP 1A2 inhibitors (e.g., ciprofloxacin, enoxacin) or strong CYP 3A4 inducers (e.g., phenytoin, carbamazepine, phenobarbital, rifampin) which cannot be safely discontinued; vulnerable populations (e.g., pregnant, nursing, incarcerated); unwilling to use reliable means of contraception; history of neuroleptic malignant syndrome; prior treatment with clozapine, prior treatment with long-acting injectable antipsychotics that are 1-month formulations within the past 3 months and for 3-month formulations within the past 6 months; intolerable side effects to either clozapine or risperidone in lifetime, or a previously failed trial of either clozapine or risperidone at adequate doses in lifetime; history of drug reaction with eosinophilia and systemic symptoms syndrome (DRESS), also known as drug-induced hypersensitivity syndrome (DIHS); high risk for suicide defined as more than 1 attempt in past 12 months that required medical attention, any attempt in the past 3 months or current suicidal ideation with plan and intent such that outpatient care is precluded; current homicidal ideation with plan and intent such that outpatient care is precluded.

Where this trial is running

Hartford, Connecticut and 4 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions SchizophreniaSchizoaffective DisorderBipolar 1 DisorderSchizophrenia, Bipolar, Psychosis, Biomarker, Biotype, BSNIP, B-SNIP, IEA
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.