Objective To evaluate the occurrence of rheumatological immune-related adverse events (irAEs) induced by immune checkpoint inhibitors (ICIs) using real-world database data.

Methods By searching the Food and Drug Administration Adverse Event Reporting System (FAERS) database, adverseevent data from January 1, 2011, to March 31, 2025, were screened. Signal detection for potential adverse events was performed employing the reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) methods.

Results A total of 2643 reports of rheumatological irAEs directly induced by ICIs were retrieved from the database. The proportion of male patients experiencing rheumatological irAEs was higher than that of female patients. The age group of 45-74 years accounted for the largest proportion (49.80%, 1316/2643). Physicians (47.26%, 1249/2643) and patients (19.11%, 505/2643) were the primary reporters. Among the drugs causing rheumatological irAEs, nivolumab was the most frequently reported (42.41%, 1121/2643), followed by pembrolizumab (35.04%, 926/2643). In terms of the distribution of rheumatological irAE types, arthritis (39.86%, 1106/2775) and rheumatoid arthritis (24.58%, 682/2775) were the most common. Four signal detection methods indicated associations between rheumatological irAEs and the use of six ICIs: nivolumab, pembrolizumab, cemiplimab, dostarlimab, avelumab, and relatlimab. Among the 819 reports with clear timing of onset, 69.72% (571/819) of adverse events occurred within 120 days after drug administration. Among the 2433 reports with clear outcomes of adverse events, 6.45% (157/2433) of patients died, 5.55% (135/2433) experienced disability, 2.47% (60/2433) had life-threatening conditions, 31.98% (778/2433) required hospitalization, and 90.59% (2204/2433) experienced other serious medical events.

Conclusions Severe rheumatological irAEs induced by ICIs and the corresponding detection signals warrant clinical attention. This study provides new evidence for the clinical monitoring and management of rheumatological irAEs, offering valuable insights for enhancing the safety of ICIs in clinical practice.