Phase 2a Open-label Study of ART5803 Antibody Treatment in Adults With Anti-NMDAR Encephalitis or Related Psychiatric Disease Aiming to Assess Safety and Preliminary Effectiveness

What this Trial Is About

Researchers are studying adults diagnosed with anti-N-methyl-D-aspartate receptor NMDAR encephalitis ANRE or anti-NMDAR autoantibody-associated psychiatric disease to evaluate the safety, tolerability, preliminary effectiveness, and how the body processes a drug called ART5803. This condition involves the immune system attacking parts of the brain, leading to loss of receptor function, and may be linked to psychiatric symptoms. The study is a Phase 2a, open-label trial led by Arialys Australia Pty Ltd. Participants will receive ART5803, a specialized antibody designed to bind the NMDAR receptor without interfering with its normal activity, while blocking harmful autoantibodies. The treatment is given by intravenous infusion initial participants receive 30 mgkg, and later participants may receive up to 60 mgkg. The schedule includes weekly infusions for 4 weeks, followed by infusions every two weeks for 8 weeks, totaling 8 doses. The study groups include adults with chronic, subacute, or acute ANRE, as well as those with anti-NMDAR autoantibody-associated psychiatric disease. During the 26-week study period, participants will undergo safety and tolerability assessments, patient-reported outcomes, neuropsychological tests, and evaluations of neurological and behavioral changes. Blood and cerebrospinal fluid samples will be collected to study how ART5803 is processed in the body. Participants will be monitored for changes in mobility, daily living activities, and psychiatric symptoms. The study aims to carefully track effects over time while ensuring participant safety.

A Study in Participants With Anti-NMDAR Encephalitis and Anti-NMDAR Autoantibody-Associated Psychiatric Disease