Late-Onset Immune-Related Adverse Events After Immune Checkpoint Inhibitor Therapy

Area of Science:

• Oncology
• Immunology
• Clinical Medicine

Background:

• Immune checkpoint inhibitors (ICIs) are increasingly used in cancer treatment.
• The frequency and risk factors for late-onset immune-related adverse events (irAEs) are not well understood.

Purpose of the Study:

• To determine the incidence of late-onset irAEs requiring hospitalization.
• To identify patient-specific risk factors associated with the development of late-onset irAEs.

Main Methods:

• Retrospective observational cohort study of patients hospitalized with irAEs after ICI therapy.
• Data collected from January 2011 to October 2022.
• Analysis focused on the timing of irAE hospitalization and associated patient factors.

Main Results:

• 10.8% of patients presented with irAEs more than 12 months after ICI initiation.
• Late-onset irAEs were more common with anti-PD-L1 monotherapy compared to dual ICI therapy.
• Kidney and hematologic irAEs were most likely to present late.
• Perioperative ICI use was associated with intermediate-interval irAEs.
• Recent ICI exposure (within 60 days) was less common in patients with late irAEs.

Conclusions:

• Late-onset irAEs can occur years after initiating immune checkpoint inhibitor therapy.
• Clinicians must maintain vigilance for irAEs irrespective of the time elapsed since ICI treatment.
• Further research is needed to elucidate risk factors and underlying mechanisms of late-onset irAEs.