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Study on Biomarkers for Predicting Response to Clozapine in Patients with Schizophrenia

Registered drugNo placebo

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial focuses on studying schizophrenia, a mental health condition that affects how a person thinks, feels, and behaves. The study is investigating the use of a medication called clozapine, which is often used to treat schizophrenia when other treatments have not been effective. Clozapine is taken orally, meaning it is swallowed in pill form.

The purpose of the study is to explore certain biological markers, known as biomarkers, that might predict how well a person with schizophrenia will respond to clozapine. Participants in the study will continue their stable antipsychotic treatment and will be monitored over a period of time to observe any changes or improvements in their symptoms. The study aims to understand the role of these biomarkers in the treatment process.

Throughout the study, researchers will also examine the permeability of the blood-brain barrier, which is a protective layer that controls what substances can enter the brain from the bloodstream. They will look at inflammatory substances in the blood and cerebrospinal fluid, which is the fluid surrounding the brain and spinal cord, to gather more information about the body's response to clozapine. The study is expected to continue until the end of 2029.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

Step 1
Initial assessment
Upon joining the study, an initial assessment will be conducted to confirm eligibility. This includes verifying the diagnosis of schizophrenia or related conditions, as well as ensuring stable antipsychotic treatment in the last month.
Eligibility criteria include being between 18 and 64 years old, legally competent, and having tried at least two antipsychotic drugs without sufficient symptom improvement.
Step 2
Medication administration
Participants will begin taking clozapine, which is administered orally. The dosage and frequency will be determined by the study team based on individual needs and responses.
The duration of clozapine administration will be specified by the study protocol and may vary depending on individual response.
Step 3
Regular monitoring
Throughout the trial, regular monitoring will be conducted to assess the response to clozapine. This includes checking for any side effects and measuring the permeability of the blood-brain barrier and inflammatory markers in the blood and cerebrospinal fluid.
Participants will be required to attend scheduled appointments for these assessments.
Step 4
Final evaluation
At the end of the trial, a final evaluation will be conducted to assess the overall response to clozapine and the presence of any biomarkers that predict response.
The study is expected to conclude by December 31, 2029, and participants will be informed of the results and any further steps if necessary.

Who can join the trial?

7 criteria

Must have a diagnosis of schizophrenia or similar conditions according to specific medical guidelines (ICD-10 codes: F20.x, F22, F25, F28/29).
Must be between the ages of 18 and 64 years.
Must be legally competent, meaning able to make decisions for oneself.
Must have been on a stable treatment with antipsychotic medication for the last month.
Must be considered treatment refractory, meaning having tried at least two different antipsychotic medications at the right dose and for at least 6 weeks without enough improvement in symptoms.
Recreational use of substances is allowed as long as it does not affect the ability to follow the study requirements.
If female and able to become pregnant, must use reliable birth control methods, such as an intrauterine device (IUD) or hormonal contraception.

Who cannot join the trial?

3 criteria

Patients who do not have a diagnosis of schizophrenia cannot participate.
Patients who are not within the specified age range cannot participate.
Patients who are part of a vulnerable population cannot participate.

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Investigated drugs

Clozapine is a medication used to treat schizophrenia, particularly in patients who have not responded well to other treatments. It works by helping to balance certain chemicals in the brain, which can reduce symptoms like hallucinations and improve mood and thinking. In this trial, clozapine is being studied to understand how it helps certain patients and to identify markers that predict a positive response to the treatment.

Clozapine

What is already known about the treatment

Clozapine – Clozapine is a medication administered orally, typically in tablet form, and is used to treat schizophrenia, particularly in patients who have not responded well to other treatments. It is currently well-established in medical practice and literature as an effective option for managing symptoms of schizophrenia. The main therapeutic indication for clozapine is schizophrenia, especially in cases where other medications have failed. At the molecular level, clozapine works by affecting neurotransmitters in the brain, particularly by blocking dopamine receptors, which helps to reduce symptoms like hallucinations and delusions. It is classified pharmacologically as an atypical antipsychotic.

Investigated diseases

Schizophrenia – Schizophrenia is a chronic mental disorder that affects how a person thinks, feels, and behaves. It often begins in late adolescence or early adulthood. The disease is characterized by episodes of psychosis, which may include hallucinations, delusions, and disorganized thinking. Over time, individuals may experience a decline in cognitive function, affecting memory, attention, and problem-solving skills. Negative symptoms, such as reduced emotional expression and lack of motivation, can also develop. The progression of schizophrenia varies, with some individuals experiencing periods of remission and others having persistent symptoms.