Long-term safety and outcomes of repeated rituximab in adults with schizophrenia spectrum disorder

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What is this study about?

The trial looks at people with Schizophrenia spectrum disorder, a mental health condition that can cause hallucinations, delusions, and difficulties thinking clearly. The study uses the medication rituximab, which works by changing the activity of the immune system. The drug is given by an infusion, a process where the medicine is slowly delivered into a vein through a small tube.

The purpose of the study is to evaluate the long‑term outcomes and safety of repeated adjuvant (additional) treatment with rituximab in this condition. Participants receive two infusions several weeks apart and are then followed for several months with regular clinic visits to check how they feel and to monitor any side effects.

During the follow‑up, doctors use simple rating scales such as the Clinical Global Impression – Improvement, which measures how much a person’s symptoms have gotten better, and the Clinical Global Impression – Severity, which rates how serious the illness is. Patients also complete short questionnaires about their overall health, daily functioning, and any changes in blood tests that may show immune system activity. Family members may be asked to give their view of any improvement as well.

1 enrollment and consent

after joining the study, a written consent form is signed to confirm participation.

the study team confirms eligibility based on the diagnosis of a schizophrenia spectrum disorder.

2 baseline assessments

a series of clinical interviews and questionnaires are completed to record current symptom severity and daily functioning.

blood samples are taken to measure baseline biomarkers.

the results create a reference point for later comparison.

3 first rituximab infusion

the medication rituximab is given as an infusion, meaning it is delivered slowly through a vein.

the dose is 100 mg (milligrams).

the infusion takes place in a clinical setting and is monitored by staff for safety.

4 post‑infusion monitoring

after the first infusion, a short observation period is required to watch for any immediate side effects.

if no adverse reactions occur, the patient can leave the clinic following the observation.

5 second rituximab infusion

a second infusion of 100 mg rituximab is administered after the interval specified by the study protocol.

the procedure is the same as the first infusion, with intravenous delivery and monitoring.

6 follow‑up assessments (approximately 4 months after the second infusion)

around four months (plus or minus one month) after the second infusion, a set of evaluations is performed.

clinical improvement is measured using the clinical global impression – improvement scale, where a score of 2.5 or lower indicates noticeable improvement.

severity of illness is assessed with the clinical global impression – severity scale.

overall functioning is evaluated with the personal and social performance scale.

the patient rates general well‑being on a visual analogue scale (a line where the ends represent worst and best health).

questionnaires about negative symptoms and overall psychiatric symptoms are completed.

an informant, such as a close relative, may also provide an improvement rating.

blood samples are taken again to check changes in biomarkers.

7 additional follow‑up visits

further assessment visits may be scheduled as defined by the study to continue monitoring safety and long‑term outcomes.

these visits repeat many of the same questionnaires and blood tests to track progress over time.

Who Can Join the Study?

You must have already taken part in the RCT‑Rits trial, which is the earlier study related to this research.
You need to sign an informed consent form, meaning you agree to join after understanding what the study involves.
Your illness must have lasted for more than 2 years, indicating a long‑standing condition.
You must meet the DSM‑5 diagnostic criteria for schizophrenia or schizoaffective disorder at the start of the earlier trial; DSM‑5 is a handbook doctors use to diagnose mental health conditions.
If you are a woman who could become pregnant, you must be willing to use contraceptives (birth control) or avoid sexual activity for the whole study period and for one year after the last dose of the medication.
You should be clear and oriented when giving consent, meaning you are aware of who you are, where you are, and the time.

Who Cannot Join the Study?

Being pregnant or breastfeeding.
Having cancer (also called malignancy) now or having had cancer within the past three years.
Having a low level of certain immune proteins called hypogammaglobulinemia or a low count of a type of white blood cell called neutropenia.
Having any other physical health problem that the doctor believes would make participation unsafe.
Weighing less than 40 kilograms (about 88 pounds).
Having a current infection that is medically important.
Having long‑term (chronic) infections.
Testing positive for hepatitis B, hepatitis C, HIV, or tuberculosis at the start of the study.
Having serious (severe) heart disease.
Being unable to understand the study and give an informed decision to consent.
Having taken other monoclonal antibody drugs, other immune‑system‑altering (immunomodulation) treatments, or chemotherapy drugs (called cytostatics) within the past year.

Where you can join this trial?

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Verified Sites

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Other Sites

Site Name	City	Country
Region Oerebro Laen	Orebro	Sweden
Region Vaesterbotten	Umea	Sweden
Region Skane Helsingborg Hospital	Helsingborg	Sweden
Rqyyqb Vshuxdstl	Karlstad	Sweden

Trial status

Country	Status	Recruitment Start
Sweden	Not yet recruiting	01.10.2026

Trial locations

Investigated drugs:

Rituximab

Rituximab is a medication that works by modifying the immune system. In this study, it is given by an intravenous infusion. The drug is being tested as an added (adjuvant) treatment for people with schizophrenia or schizoaffective disorder to see if it can improve long‑term outcomes and be safe when used repeatedly over time.

Investigated diseases:

Schizophrenia

Schizophrenia spectrum disorder – Schizophrenia spectrum disorder is a chronic mental health condition characterized by distortions in thinking, perception, emotions, and behavior. It often begins in late adolescence or early adulthood. People may experience hallucinations, delusions, disorganized speech, and reduced motivation. Over time, symptoms can fluctuate, with periods of worsening and relative stability. Social and occupational functioning may decline as the disorder progresses. The condition is considered part of a broader spectrum that includes related psychotic illnesses.

Trial ID:

2026-525324-26-00

Protocol code:

RITS-LONG

Trial Phase:

Therapeutic exploratory (Phase II)

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Long-term safety and outcomes of repeated rituximab in adults with schizophrenia spectrum disorder

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?