Arialys Advances ART5803 Development with First Phase 2 Patient Dosed and FDA IND Clearance
Tuesday, June 16, 2026
Arialys Therapeutics has announced key clinical and regulatory milestones for ART5803, its investigational treatment for autoimmune neuropsychiatric diseases. The company reported that the first patient with anti-NMDA receptor encephalitis (ANRE) has been treated in the Phase 2a ART5803-201 study, which is currently enrolling participants in South Korea.
The company also received clearance from the U.S. Food and Drug Administration (FDA) for its Investigational New Drug (IND) application supporting ART5803-202, a separate randomised Phase 2 clinical trial planned in the United States.
ART5803 is a novel therapy designed to block the harmful effects of autoantibodies that target the NMDA receptor. The treatment was developed using structural biology techniques and is intended to provide a more targeted approach for patients with autoimmune neuropsychiatric disorders.
Arialys recently completed Phase 1 single-ascending-dose and multiple-ascending-dose studies in healthy volunteers. Data presented at the 2026 Annual Meeting of the American Academy of Neurology showed a favourable safety and pharmacokinetic profile, including evidence that the therapy can cross the blood-brain barrier, supporting further clinical development.
Anti-NMDA receptor encephalitis is a rare neurological disorder that can cause severe psychiatric and neurological symptoms, often requiring intensive hospital care. There are currently no approved treatments specifically for the condition.
ART5803 is a humanised, monovalent monoclonal antibody designed to directly inhibit the disease-causing effects of NMDA receptor autoantibodies. In preclinical studies, the therapy rapidly reversed behavioural symptoms associated with NMDA receptor autoantibody activity.
The ongoing ART5803-201 trial is an open-label Phase 2a study evaluating the treatment in patients with acute and chronic ANRE, as well as psychosis patients with anti-NMDA receptor autoimmunity. The study is actively recruiting participants in South Korea.
The ART5803-202 study will be a randomised, placebo-controlled Phase 2 trial in patients with ANRE and is expected to begin in the United States during the second half of 2026.
The FDA has granted both Orphan Drug Designation and Rare Pediatric Disease Designation to ART5803, supporting its development for this rare condition.
Source: businesswire.com
