Table 1 Eligibility criteria for the RCT-R study

Inclusion criteria

 • provide informed consent

 • willing to consent to blood sampling

 • patient aged 18 to 55 years

 • duration of illness exceeding 1 year

 • diagnosed with schizophrenia spectrum disorder (SSD)

 • if female and with any risk for pregnancy, willing to use contraceptives or abstinence if normal and preferred lifestyle

 • subjects should be judged by the investigator to be lucid and oriented to person, place, time, and situation when giving the informed consent

 • insufficiently recovered from previous antipsychotic treatments

 • a minimum score of 4 in CGI-S at baseline

Exclusion criteria

 • pregnancy or breast-feeding

 • weight below 40 kg

 • clinically relevant ongoing infection at the discretion of the physician

 • chronic infections

 • positive test for hepatitis B, hepatitis C, HIV, or TB prior to treatment

 • malignancy currently or within 2 years prior to inclusion

 • current severe heart failure (NYHA grade IV) or any other severe heart disease (e.g. history of cardiac arrhythmia or myocardial infarction)

 • any change of antipsychotic medication within the previous 4 weeks

 • unable to make an informed decision to consent to the trial

 • ongoing clozapine treatment

 • ongoing immunomodulatory treatment

 • treatments with monoclonal antibodies within 1 year before the inclusion