NCT06867991

Safety and Efficacy of Combined B Cell Depleting theRapy And Daratumumab In Autoimmune Encephalitis

• Status: Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 200 (estimated)
• Sponsor: The First People's Hospital of Changzhou · Academic / Other
• Sex: All
• Age: 12 Years
• Healthy volunteers: Not accepted

Summary

Autoimmune encephalitis is an autoimmune disease of the central nervous system that targets neuronal autoantigens. Anti-neuronal autoantibodies are produced in patients, with anti-NMDAR antibody being the most common.Anti-NMDAR encephalitis can be severe and life-threatening. Anti-NMDAR autoantibodies against neurons are pathogenic and are mainly produced by autoreactive B cells and plasma cells. Therefore, early elimination of these abnormal immune cells is crucial for rapid improvement of the patient's condition. This study aims to explore the efficacy and safety of B cell depletion therapy (ofatumumab) followed by plasma cell depletion therapy (daratumumab) in the treatment of severe anti-NMDAR autoimmune encephalitis.

Detailed description

Autoimmune encephalitis (AE) is a broad spectrum of immune-mediated neuropsychiatric diseases, usually associated with antibodies against surface proteins, ion channels, synapses or intracellular proteins of neuronal cells. Anti-N-methyl-D-aspartate receptro (NMDAR) encephalitis is the most common type of AE.The clinical manifestations include behavioral changes, psychiatric symptoms, epileptic seizures, memory and cognitive deficits, abnormal movements, autonomic dysfunction and decreased consciousness. Most children and adult patients present with a syndrome that combines the above symptoms and can be severe. Early initiation of immunotherapy is necessary to improve clinical prognosis and reduce its recurrence. However, no disease-modifying therapy specifically for AE has been approved. A variety of therapies have emerged for severe autoimmune encephalitis, including anti-CD20 monoclonal antibody rituximab, proteasome inhibitor bortezomib, anti-CD38 monoclonal antibody daratumumab, anti-IL-6R monoclonal antibody tocilizumab, low-dose IL-2, and intrathecal methotrexate. The evidence for the efficacy of these drugs mostly comes from case reports, and there are currently no high-quality randomized controlled clinical studies reported. Studies have found that anti-NMDAR antibody is produced by autoreactive B cells and plasma cells. Among these cells, long-lived plasma cells in the intrathecal, meningeal, and brain parenchyma are responsible for the production of pathogenic antibodies in severe cases. The B cell-depleting therapeutic antibody rituximab targets CD20-positive B cells. CD138-positive plasma cells lack CD20 surface receptors, are not targeted by rituximab, and are also resistant to other immunosuppressive therapies. Daratumumab is an anti-CD38 antibody that can target long-lived plasma cells and has shown good therapeutic responses in autoimmune hemolytic anemia, systemic lupus erythematosus, and autoimmune encephalitis, with an acceptable safety profile. Daratumumab not only works by clearing plasma cells, but also regulates certain T cell functions. RADIA study is an investigator-initiated, randomized, controlled, open-label, multicenter clinical trial to investigate the safety and efficacy of anti-CD20 mAb ofatumumab in combination of anti-CD38 mAb daratumumab in patients with severe anti-NMDAR encephalitis.

Conditions

• Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Interventions

Type	Name	Description
DRUG	Ofatumumab combined with daratumumab	All participants will begin acute first-line therapy prior to randomization, and participants who were receiving oral or intravenous corticosteroids at baseline will need to taper their doses according to a standard taper schedule starting 4 weeks after randomization (week 4). Patients will be randomly assigned to receive ofatumumab followed by daratumumab or ofatumumab followed by repeated intravenous globulin. The ofatumumab group will receive subcutaneous ofatumumab at weeks 0, 1, 2, 4, 8, 12, 16, 20, and 24, while the ofatumumab-daratumumab group will receive daratumumab intravenously (on the second day of ofatumumab) in addition to ofatumumab, with a dose of 8 mg/kg at weeks 0, 1, 2, and 4, and a dose of 4 mg/kg at weeks 8, 12, 16, 20, and 24. The study will investigate the effects of up to 24 cycles of daratumumab.
DRUG	Ofatumumab	All participants were started on acute first-line therapy before randomization, and participants who were receiving oral or intravenous glucocorticoids at baseline were required to taper their doses according to a standard taper schedule starting 4 weeks after randomization (week 4). Ofatumumab was administered subcutaneously at weeks 0, 1, 2, 4, 8, 12, 16, 20, and 24 in the ofatumumab group.
DRUG	Repeated intravenous immunoglobulin/plasma exchange therapy	Repeated intravenous immunoglobulin/plasma exchange therapy

Timeline

• Start date: 2024-11-08
• Primary completion: 2026-11-08
• Completion: 2027-11-08
• First posted: 2025-03-10
• Last updated: 2025-07-15

Locations

2 sites across 1 country: China