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CLOZAPINE Response in Biotype-1

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

Status
Recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04580134
Enrollment
524
Registered
2020-10-08
Start date
2022-03-01
Completion date
2027-04-30
Last updated
2026-05-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bipolar 1 Disorder, Schizoaffective Disorder, Schizophrenia

Keywords

Schizophrenia, Bipolar, Psychosis, Biomarker, Biotype, BSNIP, B-SNIP, IEA

Brief summary

The CLOZAPINE study is designed as a multisite study across 5 sites and is a clinical trial, involving human participants who are prospectively assigned to an intervention. The study will utilize a stringent randomized, double-blinded, parallel group clinical trial design. B2 group will serve as psychosis control with risperidone as medication control. The study is designed to evaluate effect of clozapine on the B1 participants, and the effect that will be evaluated is a biomedical outcome. The study sample will be comprised of individuals with psychosis, including 1) schizophrenia, 2) schizoaffective disorder and 3) psychotic bipolar I disorder. The investigators plan to initially screen and recruit n=524 (from both the existing B-SNIP library and newly-identified psychosis cases, \ 50% each) in order to enroll n=320 (B1 and B2) into the RCT.

Detailed description

The clinical hypotheses underlying this experiment are that (i) B1 individuals are uniquely responsive to the pharmacological properties of clozapine because they have low Intrinsic EEG Activity (IEA), an index of compromised cortical neuronal responsiveness. This is plausibly associated with both (ii) reduced excitatory and (iii) reduced inhibitory stimulation in cortex and that IEA will track this altered excitatory/inhibitory balance and parallel clinical antipsychotic response. Furthermore, (iv) B2 probands (based on their high IEA) will not respond to clozapine. In this study clozapine response is measured by a 'super-APD' (AntiPsychotic Drug) drug response, a response in addition to what is seen with a usual APD (e.g., risperidone). The investigators believe that the 30-35% of individuals who show a 'super-APD' clozapine response in schizophrenia in the pivotal study will be predominantly in B1, because the B1 completers will no longer be diluted by the other non-responders like B2s. Therefore, the investigators postulate that \>50% of B1 will show a unique therapeutic action of clozapine (beyond general APD action), contrasted with the usual predicted response of B1 to risperidone or of B2 to clozapine or risperidone.

Interventions

DRUGclozapine

Biotype 1 and Biotype 2

DRUGrisperidone

Biotype 1 and Biotype 2

Sponsors

University of Texas Southwestern Medical Center
Lead SponsorOTHER
National Institute of Mental Health (NIMH)
CollaboratorNIH
Beth Israel Deaconess Medical Center
CollaboratorOTHER
Hartford Hospital
CollaboratorOTHER
University of Georgia
CollaboratorOTHER
University of Chicago
CollaboratorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

All participants and those who interact with them are blinded to study medication. The pharmacy dispensing team and the Safety Officer will remain unblinded for safety reasons.

Intervention model description

Individuals who previously participated in a B-SNIP trial who have already been biotyped will be grouped accordingly. New incoming individuals will have their Biotype completed. Those with Biotypes 1 and 2 will be recruited into this protocol. Anyone with Biotype 3 will be excluded from this protocol, but their information will be retained for use in a later study. Biotypes 1 and 2 will be separated into two groups. Each Biotype, B1 and B2, will be randomized between risperidone and clozapine to create parallel comparator groups.

Eligibility

Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Change in the PANSS total scoreWeek 4, Week 10 and Week 18The change in the PANSS total score from the clinical trial baseline (W4) to the end of treatment (W18) will be a primary outcome measure. We predict that B1/clozapine will show a significantly larger change in the PANSS score from W4 to W18, compared to B1/risperidone, B2/clozapine and B2/risperidone. We will also examine the patterns of change in the PANSS score during the 'stable treatment' phase (W10-W18), across the same study groups. A mixed-effect repeated-measures ANCOVA \[2(Biotypes) × 2(clozapine/risperidone) × 2(time points\] will be used. We also predict that the reduction in the PANSS scores will correlate with increased IEA in B1/clozapine but not in B1/risperidone, B2/clozapine or B2/risperidone. Multivariate prediction models will be used.

Countries

United States

Contacts

CONTACTAsha Philip
asha.philip@utsouthwestern.edu214-648-5276
CONTACTEmily McNeil
emily.mcneil@utsouthwestern.edu214-648-1683
PRINCIPAL_INVESTIGATORCarol Tamminga, M.D.

University of Texas Southwestern Medical Center

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 12, 2026