A multidimensional investigation of myelosuppression associated with sintilimab: integrating pharmacovigilance signal mining with real-world clinical evidence.

Objective: Sintilimab, a programmed cell death protein 1 (PD-1) inhibitor, is widely used in cancer immunotherapy, but its hematological toxicity profile in real-world settings remains incompletely understood. This study aims to comprehensively investigate the risk and characteristics of sintilimab-induced myelosuppression through integrated pharmacovigilance and clinical cohort analyses. Methods: We analyzed FDA Adverse Event Reporting System data (Q1 2020-Q2 2025) for sintilimab-associated adverse events using disproportionality analyses (Reporting Odds Ratio, Proportional Reporting Ratio). Time-to-onset was modeled using Weibull distribution, and risk factors were identified Results: Among 668 FAERS reports, myelosuppression was the most frequent hematological adverse event (n = 146) with a strong signal (ROR = 51.86). In the clinical cohort, 67.06% developed myelosuppression, with 86.47% classified as Grade III/IV. Median onset was 14 days (IQR 5-30), with highest risk early in treatment. Independent risk factors included female sex (OR = 0.457, p = 0.013), paclitaxel use (OR = 4.129, p = 0.004), cisplatin use (OR = 2.240, p = 0.020), and advanced M stage (OR = 0.871, p = 0.006). Conclusion: Myelosuppression is a common, early-onset, and severe adverse event associated with sintilimab, particularly in patients receiving concomitant chemotherapy or with advanced disease. These findings underscore the need for intensified hematologic monitoring and personalized risk stratification in clinical practice.