Immune-related encephalitis after immune checkpoint inhibitor therapy

Area of Science:

• Neuro-oncology
• Immunology
• Neurology

Background:

• Immune checkpoint inhibitors (ICI) are vital cancer therapies.
• ICI can induce immune-related encephalitis (IrE), a serious neurological complication.
• This study presents a large case series and literature review of IrE in ICI-treated patients.

Purpose of the Study:

• To characterize the clinical presentation, diagnosis, and treatment of immune-related encephalitis in cancer patients receiving ICI.
• To evaluate treatment outcomes and the safety of resuming ICI after IrE.
• To inform management guidelines for neurological immune-related adverse events.

Main Methods:

• Retrospective analysis of 14 patients with ICI-associated encephalitis.
• Comprehensive literature review of 132 additional cases.
• Analysis of diagnostic findings (CSF, MRI, EEG, autoantibodies) and treatment responses.

Main Results:

• Cerebrospinal fluid (CSF) abnormalities and autoantibodies were common diagnostic findings.
• Corticosteroids were the primary treatment, often supplemented with IVIg or rituximab.
• Most patients (86%) showed significant recovery, with a low rate of relapse (10%) after treatment.
• Anti-cancer responses were maintained or achieved in most patients despite IrE.

Conclusions:

• Immune-related encephalitis is a treatable condition with favorable outcomes, particularly with prompt corticosteroid treatment.
• Additional immunosuppression may be necessary for refractory cases.
• Relapse of encephalitis is uncommon, and ICI can often be safely resumed, supporting updated management guidelines.