Immunotherapy for antibody-associated psychosis

A Randomised Phase II Double-blinded Placebo-controlled Trial of Intravenous Immunoglobulins and Rituximab in Patients with Antibody-associated Psychosis (SINAPPS2)

Phase 2 Interventional University of Cambridge · NCT03194815

This study is testing if a combination of two immunotherapy treatments can help people with acute psychosis caused by certain antibodies feel better and stay well.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment70 (estimated)
Ages16 Years to 70 Years
SexAll
SponsorUniversity of Cambridge Academic / other
Drugs / interventionsrituximab, immunotherapy
Locations10 sites (Cambridge and 9 other locations)
Trial IDNCT03194815 on ClinicalTrials.gov

What this trial studies

This phase II trial investigates the effectiveness of immunotherapy, specifically intravenous immunoglobulin (IVIG) and rituximab, in treating patients with acute psychosis linked to anti-neuronal membranes. The study is designed as a randomized, double-blinded, placebo-controlled trial to ensure unbiased results. Participants will receive a cycle of IVIG followed by rituximab infusions, aiming to induce and maintain remission from psychosis symptoms. The trial also assesses the safety of this treatment approach for the targeted patient population.

Who should consider this trial

Good fit: Ideal candidates include individuals experiencing acute psychosis for more than two weeks with detectable neuronal membrane autoantibodies.

Not a fit: Patients with chronic psychosis lasting over 24 months or those with severe neurological diseases may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients suffering from antibody-associated psychosis.

How similar studies have performed: Previous studies exploring immunotherapy for similar conditions have shown promising results, suggesting potential efficacy in this novel application.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Acute psychosis \>2 weeks. This may either be first episode or relapse after remission (remission defined as having mild or absent symptoms of psychosis for at least 6 months)
* Serum or CSF neuronal membrane autoantibodies at pathological levels (including NMDAR, LGI1 and other)
* Psychosis symptoms as defined by PANSS ≥4 on at least one of the following items: P1, P2, P3, N1, N4, N6, G5 and G9.

Exclusion Criteria:

* Current episode of psychosis greater than 24 months duration
* Co-existing severe neurological disease
* Evidence of current acute encephalopathy
* Hepatitis or HIV infection, pregnancy
* Contraindications to any trial drug
* Concurrent enrolment in another CTIMP

Where this trial is running

Cambridge and 9 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions PsychosisAutoimmune EncephalitisImmunotherapyAutoantibodies
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.