Hematological toxicities and thrombosis risk associated with immune checkpoint inhibitors: a pharmacovigilance study from 2014 to 2024

BACKGROUND: Immune checkpoint inhibitors (ICIs) have significantly improved clinical outcomes in a wide range of cancers but may also induce hematological toxicities and thrombosis risk. This study comprehensively evaluated hematological and thrombotic adverse events (AEs) associated with ICIs in real-world settings using the FDA Adverse Event Reporting System (FAERS) database, aiming to characterize their clinical features. METHODS: Data were extracted from the FAERS database (Q1 2014 to Q4 2024) for disproportionality analysis. AEs were classified using the Medical Dictionary for Regulatory Activities (MedDRA). Associations between ICIs and hematological/thrombotic AEs were assessed via the reporting odds ratio (ROR) and Bayesian Confidence Propagation Neural Network (BCPNN) methods. Clinical characteristics of affected patients were analyzed, and time-to-onset across ICI regimens was further evaluated. RESULTS: We identified 14,753 ICI-associated hematological toxicities and thrombotic events. Among reports with available sex information, a higher reporting frequency was observed in men (50.90%) than in women (40.11%). The most frequent AEs were anemia (2963 cases, 16.62%), thrombocytopenia (1961, 11.00%), febrile neutropenia (1935, 10.85%), neutropenia (1392, 7.81%), myelosuppression (979, 5.49%), pancytopenia (739, 4.14%), lymphadenopathy (475, 2.66%), disseminated intravascular coagulation (DIC; 468, 2.62%), leukopenia (468, 2.62%), and deep vein thrombosis (DVT; 213, 1.19%). The median time-to-onset for ICI monotherapy-associated AEs was 28 days (IQR 11-79), with 78.22% occurring within 3 months. Notably, DIC and DVT had the highest mortality proportion among the top 10 AEs. CONCLUSION: Hematological and thrombotic AEs associated with ICI therapy show notable reporting frequencies in FAERS. Combination regimens demonstrated stronger reporting signals for certain events. These AEs frequently showed early reporting and notable mortality proportions, highlighting the importance of clinical vigilance. Further studies are needed to confirm these findings.