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

A monovalent (one-armed) antibody, that binds to the NTD of the NMDAR NR1 subunit without causing NMDAR inhibition, activation, or receptor internalization, while simultaneously blocking the ability of the pathogenic anti-NMDAR autoantibodies to bind to the receptor. 1. Sentinel participants: 30 mg/kg 2. Subsequent participants: up to 60 mg/kg 3. Schedule: Q1W for 4 doses then Q2W for 4 doses

A monovalent (one-armed) antibody, that binds to the NTD of the NMDAR NR1 subunit without causing NMDAR inhibition, activation, or receptor internalization, while simultaneously blocking the ability of the pathogenic anti-NMDAR autoantibodies to bind to the receptor. Participants receive ART5803 by intravenous infusion once a week for 4 weeks, then every 2 weeks for 8 weeks, for a total of 8 doses. Sentinel participants receive 30 mg per kg. Additional participants may receive up to 60 mg per kg based on Safety Review Committee guidance.