An Exploratory Analysis of Immune and Inflammatory Response Associated With Clozapine

October 4, 2023 updated by: Walter Stearns, Ohio State University

An Exploratory Analysis of Immune and Inflammatory Response Associated With Clozapine Versus Non-Clozapine Antipsychotics in Individuals With Treatment-resistant Schizophrenia

The specific aim of this protocol is to compare Clozapine treatment vs Non-Clozapine antipsychotic treatment in a population of treatment-refractory individuals with schizophrenia. Specifically, it is to test if Clozapine leads to a decrease in levels of inflammatory markers, namely interleukin-6 but with an exploratory view of other markers. Clozapine has superior efficacy and is the only medication approved for treatment-refractory schizophrenia in addition to decreasing the risk of suicidal behavior as well. It is unclear why Clozapine has increased efficacy from a mechanistic viewpoint. We will look at the role of inflammatory markers and assess them 1x along with rating scales for psychosis and suicidality, the other entities which Clozapine has been shown to improve.

Study Overview

Detailed Description

This study is designed to investigate if treatment with the antipsychotic Clozapine is associated with changes in various immune and inflammatory biomarkers when compared to treatment with non-Clozapine antipsychotic treatments. Clozapine is a uniquely efficacious treatment of psychotic disorders, the only effective agent in approximately 30-40% of individuals with treatment refractory symptoms. Clozapine, unlike other antipsychotic drugs, often precipitates a unique, multi-systemic inflammatory response most widely recognized in the cardiovascular system but also likely the central nervous system (CNS) which is tied into its unique side effect profile but might also account for its increased efficacy. Schizophrenia spectrum disorders affect about 1% of the population with around 30-40% of those diagnosed with symptoms refractory to standard, non-Clozapine antipsychotic treatment. We will measure various inflammatory markers 1x for patients who are stable outpatients. Participants will be patients with treatment-resistant schizophrenia on clozapine treatment for at least 6 months referred from OSU's outpatient clinic with a comparator group also referred from Ohio State University, having shown treatment resistant symptoms but with provider/patient electing not to use clozapine for clinically relevant reasons and have been on antipsychotic medication for at least 6 months. The study includes 1 visit including symptom rating scale assessments and laboratory draw for collection of serum samples and the visit also having more diagnostic assessments to assure proper enrollment. If the study results are positive meaning there is a difference between the two groups, it would help elucidate the potential mechanisms by which Clozapine works and demonstrates increased efficacy for those with treatment-refractory schizophrenia, a severely debilitating, life long illness with marked disability. This would also allow for further studies to explore this mechanism and the role of inflammation and the immune system as well.

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 40 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • All participants:

    • Between 18 and 65 years of age
    • Physically healthy (no clinically significant unstable medical condition as confirmed by medical history and physical examination)
    • Able to give informed consent
    • Treatment-Refractory Schizophrenia

Clozapine treatment group (n = 30) Individuals treated with Clozapine consistently for a minimum of 6 months

Non-Clozapine treatment group Continued treatment with non-Clozapine antipsychotic but would be eligible for Clozapine with the provider/patient electing to not pursue such for clinical reasons, consistently treated for at least 6 months

Exclusion Criteria:

  • Clinically significant medical condition; cardiovascular, pulmonary, endocrine, or renal condition requiring in depth medical treatment
  • Active or recent (within 4 weeks) bacterial or viral infection
  • Chronic viral infection (hepatitis, HIV)
  • History of autoimmune, or chronic inflammatory condition
  • Current treatment with lithium
  • Treatment with Clozapine in the past 6 months
  • Current treatment with immunomodulatory or anti-inflammatory therapy
  • Vaccination within the past 3 months
  • Current alcohol or substance use disorder of moderate or severe severity
  • Intellectual disability (i.e. intelligence quotient <70)
  • Unwilling or unable to sign informed consent document
  • Pregnancy
  • Any patient deemed ineligible by PI discretion

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Clozapine Arm
Patients will be on Clozapine for at least 6 months
We will assess inflammatory/immune marker labs
Active Comparator: Non-Clozapine arm
Patients will be on non-Clozapine antipsychotic for at least 6 months
We will assess monitor inflammatory/immune marker lab
Other Names:
  • Including Olanzapine, Risperidone, Paliperidone, Quetiapine, Aripiprazole, Ziprasidone, Lurasidone, Cariprazine, and all Typical antipsychotics

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Interleukin-6 (IL-6)
Time Frame: Up to 1 year
Comparison in interleukin-6 between Clozapine and non-Clozapine group
Up to 1 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Other immune/cardiac markers
Time Frame: Up to 1 year
Comparison in hsCRP, interleukin-1β, interferon-γ, transforming growth factor-β, tumor necrosis factor between Clozapine and non-Clozapine group
Up to 1 year
Positive and Negative Syndrome symptom Scale
Time Frame: Up to 1 year
Comparison in psychosis rating scales (PANSS) between Clozapine and non-Clozapine group. Higher scores indicate more severe symptoms of psychosis. Score from 30-210
Up to 1 year
Self-injurious Thoughts and Behaviors Interviews
Time Frame: Up to 1 year
Comparison between Clozapine and non-Clozapine group in Suicidality rating scales. Scores on rating will be binary (yes/no) for suicidal ideation and also suicide attempts.
Up to 1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 16, 2023

Primary Completion (Estimated)

March 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

January 20, 2023

First Submitted That Met QC Criteria

February 22, 2023

First Posted (Actual)

February 23, 2023

Study Record Updates

Last Update Posted (Actual)

October 6, 2023

Last Update Submitted That Met QC Criteria

October 4, 2023

Last Verified

October 1, 2023

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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