Longitudinal Cohort Study of Immune-Related Adverse Events in Solid Tumor Patients Treated With Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) have transformed the treatment of solid tumors but are associated with immune-related adverse events (irAEs) that can affect virtually any organ system. While many irAEs are well recognized, neurological, neurocognitive, and psychiatric toxicities remain diagnostically challenging, potentially severe, and poorly understood, with limited predictive biomarkers. This prospective longitudinal observational cohort study enrolls adult patients with solid tumors initiating a new course of ICI therapy. Participants undergo standardized baseline clinical assessments and biospecimen collection prior to ICI initiation, followed by longitudinal follow-up and event-driven sampling. Patients are dynamically assigned to organ-specific irAE cohorts based on the first clinically significant irAE that dictates management. Patients without grade ≥2 irAEs during follow-up serve as a comparator control cohort. The primary objective is to characterize longitudinal immune and inflammatory biomarker trajectories associated with the development of irAEs and to identify predictive and prognostic biomarkers, with particular emphasis on neurological, neurocognitive, and psychiatric toxicities. Integrated clinical, imaging, and multi-omics data will be used to elucidate mechanisms of toxicity and inform future risk stratification and personalized management strategies.